Proboscis sentence example

proboscis
  • A proboscis absent, but jaws usually present.
    33
    12
  • The proboscis bears at its extremity a circlet of smaller oral tentacles.
    14
    9
  • The stomach may be drawn out into the manubrium, forming a proboscis (" Magenstiel ") of considerable length.
    11
    8
  • To reach the honey in the spur of the flower, the insect must thrust its proboscis into the flower close under the globular head of the stigma.
    2
    0
  • Proboscis present, but short.
    11
    10
    Advertisement
  • - Note the simple snout or rostrum not introverted as a " proboscis."
    1
    0
  • Shell turriculated and siphonated, thick, each whorl with varices; foot broad and truncated anteriorly; pallial siphon well developed; proboscis present.
    7
    6
  • The sucker-bearing processes of Pneumonoderma are outgrowths of the proboscis.
    1
    0
  • Mandibles rarely present, adapted for piercing; first maxillae with palps; second maxillae forming with hypopharynx a suctorial proboscis.
    1
    0
  • Biting mandibles; second maxillae incompletely or completely fused; often forming a suctorial proboscis.
    1
    0
    Advertisement
  • - The organ most characteristic of a Nemertine is without doubt the proboscis.
    1
    0
  • this fluid to impinge against the anterior Pr, Proboscis.
    1
    0
  • On the other hand, they are much less considerably or even insignificantly so in the genera that are known to make a rather sparing use of their proboscis.
    1
    0
  • The rhynchocoel is formed by a split which appears in the mesoblast surrounding the epiblastic pit which is the forerunner of the proboscis.
    1
    0
  • - Proboscis with stylet, " reserve " sacs and muscular bulb of a Hoplonemertine.
    1
    0
    Advertisement
  • - The armature from the proboscis of Drepanophorus.
    1
    0
  • In addition to the musculature of the proboscis and proboscidian sheath, longitudinal muscular fibres are found in the walls of the oesophagus, whilst transverse ones are numerous and united into vertical dissepiments between the successive intestinal caeca, thus bringing about a very regular internal metamerization.
    1
    0
  • This is brought about by a double commissure, of which the ventral portion is considerably thicker than the dorsal, and which, together with the brain-lobes, constitutes a ring through which both proboscis and proboscidian sheath pass.
    1
    0
  • P.N., Nerves for proboscis.
    1
    0
  • nerves for the proboscis, those for the sense organs in the head and the strong nerve pair (n.
    1
    0
    Advertisement
  • Two lateral, shallow pits occur on the side of the body about the level of the hinder end of the proboscis in some species of the genus Carinella, which are termed side-organs.
    1
    0
  • As to the organ of touch, the great sensitiveness of the body has already been noticed, as well as the probable primary significance of the proboscis.
    1
    0
  • The proboscis is an invagination from the epiblast; the proboscidian sheath appears in the mesoblast, but is perhaps originally derived from the hypoblast.
    1
    0
  • B, The proboscis of one still more highly magnified.
    1
    0
  • The body is divisible into a proboscis and a trunk with sometimes an intervening neck region.
    1
    0
    Advertisement
  • The proboscis bears rings of recurved hooks arranged in horizontal rows, and it is by means of these hooks that the animal attaches itself to the tissues of its host.
    1
    0
  • Like the body, the proboscis is hollow, and its cavity is separated from the body cavity by a septum or proboscis sheath.
    1
    0
  • Traversing the cavity of the proboscis are muscle-strands inserted into the tip of the proboscis at one end and into the septum at the other.
    1
    0
  • Except for the absence of 'the longitudinal fibres the skin of the proboscis resembles that of the body, but the fluid-containing tubules of the latter are shut off from those of the body.
    1
    0
  • The canals of the proboscis open ultimately into a circular vessel which runs round its base.
    1
    0
    Advertisement
  • a, The proboscis not fully ex- h, One of the spaces in the sub b, Proboscis-sheath.
    1
    0
  • Each consists of a prolongation of the syncytial material of the proboscis skin, penetrated by canals and sheathed with a scanty muscular coat.
    1
    0
  • They seem to act as reservoirs into which the fluid of the tense, extended proboscis can withdraw when it is retracted, and from which the fluid can be driven out when it is wished to expand the proboscis.
    1
    0
  • A, The larva of Echinorhynchus proteus from the body cavity of Phoxinus laevis, with the proboscis retracted and the whole still enclosed in a capsule.
    1
    0
  • B, A section through the same; a, the invaginated proboscis; b, proboscis sheath; c, beginning of the neck; d, lemniscus.
    1
    0
    Advertisement
  • With no proboscis.
    1
    0
  • Nose and upper lip elongated into a flexible, mobile snout or short proboscis, near the end of which the nostrils are situated.
    1
    0
  • The name has reference to the tongue-shaped muscular proboscis by which the animal works its way through the sand.
    1
    0
  • The proboscis is not the only organ of locomotion, being assisted by the succeeding segment of the body, the buccal segment or collar.
    1
    0
  • By the waves of contraction executed by the proboscis accompanied by inflation of the collar, progression is effected, sometimes with marvellous rapidity.
    1
    0
    Advertisement
  • In accordance with this manner of feeding, the mouth is kept permanently open and prevented from collapsing by a pair of skeletal cornua belonging to a sustentacular apparatus (the nuchal skeleton), the body of which lies within the narrow neck of the proboscis; the latter is inserted into the collar and surrounded by the anterior free flap of this segment of the body.
    1
    0
  • The proboscis-pores are highly variable, and frequently only one is present, that on the left side; sometimes the pore-canals of the proboscis unite to open by a common median orifice, and sometimes their communication with the probosciscoelom appears to be occluded, and finally the pore-canals may be quite vestigial.
    1
    0
  • The proboscis-gut occurs as an outgrowth from the anterior dorsal wall of the collar-gut, and extends forward into the basal (posterior) region of the proboscis, through the neck into the proboscis-coelom, ending blindly in front.
    1
    0
  • In the neck of the proboscis the fibrous layer is greatly thickened, and other intensifications of this layer occur in the dorsal and ventral middle lines of the trunk extending to the posterior end of the body.
    1
    0
  • vs, ventral septum of proboscis.
    1
    0
    Advertisement
  • The anthers shed their pollen into this groove, either of themselves or when the pistil is shaken by the insertion of the bee's proboscis.
    1
    0
  • The proboscis, passing down this groove to the spur, becomes dusted with pollen; as it is drawn back, it presses up the lip-like valve of the stigma so that no pollen can enter the stigmatic chamber; but as it enters the next flower it leaves some pollen on the upper surface of the valve, and thus cross-fertilization is effected.
    1
    0
  • - One of the Nymphonomorphous Pantopoda, Nymphon hispidum, showing the seven pairs of appendages I to 7; ab, the rudimentary opisthosoma; s, the mouth-bearing proboscis.
    1
    0
  • - Appendages of 1st pair bisegmented, without poison gland; of 2nd pair prehensile, their basal segments underlying the proboscis, and furnished with sterno 1 to i 1, Somites of the opisthosoma (mesosoma plus metasoma).
    1
    0
  • Proboscis free, not supported from below by either the prosternum or the basal segments of the appendages of the 2nd pair.
    1
    0
    Advertisement
  • Appendages of 2nd pair very large and completely chelate, their basal segments meeting in the middle line, as in the Uropygi, and provided in front with membranous lip-like processes underlying the proboscis.
    1
    0
  • The projecting feature above the mouth, to which the word is usually restricted in man, is, in the case of the lower animals, called snout or muzzle, or, if much prolonged, proboscis or trunk.
    1
    0
  • C, portion of a proboscis showing the two forms of hooks; highly magnified.
    1
    0
  • The palpi vary in form and in the number of their component segments, and the proboscis, though usually straight, may be curved (as in Megarhinus) or otherwise modified in shape.
    1
    0
  • all ordinary mosquitoes), and the Culicimorphae or forms without a piercing proboscis (Mochlonyx, Corethra, &c.).
    1
    0
  • The divisions of the Siphonatae are the Ankylorhynchae (genera with curved proboscis, e.g.
    1
    0
  • Megarhinus and Toxorhynchites) and Orthorhynchae (genera with straight proboscis).
    1
    0
  • The Anophelinae have narrow bodies, and generally spotted wings, and when at rest keep body and proboscis in a straight line, often at a considerable angle with the supporting surface; in this way they can be distinguished from Culicinae, which have a humped-up thorax with which the proboscis forms an angle, and in the resting position keep the body parallel to the support.
    1
    0
  • The former is specially modified in a few genera in a manner analogous to the "proboscis" of certain Rhabdocoel Turbellaria.
    1
    0
  • In appearance tsetse are somewhat narrow-bodied flies, with a prominent proboscis, which projects horizontally in front of the head, and with the wings in the resting position closed flat one over the other like the blades of a pair of scissors.
    1
    0
  • The length of the body, exclusive of the proboscis, which measures about a line to a line and a half, varies according to the species from 6 or 8 millimetres in the case of G.
    1
    0
  • In all tsetse-flies the proboscis in the living insect is entirely concealed by the palpi, which are grooved in their inner sides and form a closely fitting sheath for the piercing organ; the base of the proboscis is expanded beneath into a large onion-shaped bulb, which is filled with muscles.
    1
    0
  • The head of the insect contains a muscular pharynx by means of which the blood from the wound inflicted by the proboscis (labium) is pumped into the alimentary canal and the so-called sucking-stomach.
    1
    0
  • The tip of the proboscis is armed with a complicated series of chitinous teeth and rasps, by means of which the fly is enabled to pierce the skin of its victim; as usual in Diptera the organ is closed on the upper side by the labrum, or upper lip, and contains the hypopharynx or common outlet of the paired salivary glands, which are situated in the abdomen.
    1
    0
  • The proboscis of tsetse-flies is without the paired piercing stilets (mandibles and maxillae) possessed by other bloodsucking Diptera, such as the female horse-flies and mosquitoes.
    1
    0
  • The act of feeding, in which the proboscis is buried in the skin of the victim nearly up to the bulb, is remarkably quick, and in thirty seconds or less the abdomen of the fly, previously flat, becomes swollen out with blood like a berry.
    1
    0
  • Macmillan & Co., Ltd.) b, bristle; cs, caudal spine; ph, pharynx; s s', the spines on the two segments of the proboscis; sg, salivary glands; st, stomach.
    1
    0
  • round the proboscis and in the two posterior caudal spines.
    1
    0
  • Enderlein has recently shown that the jaws of the Hemiptera can be recognized in a reduced condition in connexion with the louse's proboscis, the modification is so excessive that the group certainly deserves ordinal separation.
    1
    0
  • The insect is fixed by its proboscis, but moves its abdomen about and lays thirty to forty yellow eggs in small clusters.
    1
    0
  • They move actively about for a few days and then, having selected a convenient place on the young roots, insert their proboscis and become stationary.
    1
    0
  • These forms are termed the stock-mothers; they creep into the buds of the vine, and, as these develop intofthe young leaves, insert their proboscis into the upper side.
    1
    0
  • These are very simple, open and generally regular flowers, white, greenish-yellow or yellow in colour and are chiefly visited by insects with a short proboscis, such as short-tongued wasps and flies, also beetles and more rarely bees.
    1
    0
  • White and yellow colours predominate and insects with a proboscis of medium length are the common pollinating agents, such as short-tongued bees.
    1
    0
  • Hymenopterid flowers, which fall into the following groups: Bee-flowers proper, humble-bee flowers requiring a longer proboscis to reach the nectar, wasp-flowers such as fig-wort (Scrophularia nodosa) and ichneumon flowers such as tway-blade (Listera ovata).
    1
    0
  • 3, The same, when disturbed by the entrance of the proboscis of the bee in the direction of the arrow; f, filament; c, connective; s, the obstructing half of the anther.
    1
    0
  • Lepidopterid flowers, visited chiefly by Lepidoptera, which are able to reach the nectar concealed in deep, narrow tubes or spurs by means of their long slender proboscis.
    1
    0
  • c. Pinch-trap flowers, as in the family Asclepiadaceae, where the proboscis, claw or bristle of the insect is caught in the clip to which the pairs of pollinia are attached.
    1
    0
  • Other ciliated organs to be noticed are the proboscis cup of Bdelloidaceae, and the toes of Pedalion.
    1
    0
  • In Bdelloidaceae this may alternate with a leech-like gait; the corona being withdrawn, the cupped end of the proboscis serves as a sucker for attachment alternately with the adherent foot, so that the animal loops its way along.
    1
    0
  • - a, Microcodon clavus, showing corona, lateral antennae and jointed foot; b, Rhinops vitrea, corona from below, showing proboscidiform extension containing eyes; c, Philodina megalotrocha; d, head of Rotifer macroceros, postero-ventral view, showing lobes of corona, and antero-dorsal median antenna, telescopic with setae; e, Rotifer (Actinurus) neptunius, showing head with retracted corona, and protruded dorsal proboscis bearing median antenna, and telescopic foot with toes and spurs; f.
    1
    0
  • Bdelloidaceae; foot with two toes and accessory spurs or a simple perforated disk; body telescopic at either end, with an antero-dorsal proboscis ending in a ciliate cup and bearing the proximal antenna; corona usually bilobed, very wheel-like.
    1
    0
  • (eyeless); Adineta Hudson is eyeless with the corona uniformly ciliated, and proboscis adnate, hooked.
    1
    0
  • a, Proboscis.
    1
    0
  • b, Proboscis sheath.
    1
    0
  • c, Retractor of the proboscis.
    1
    0
  • f, f, Retractors of the proboscis sheath.
    1
    0
  • a, Proboscis; b, bulla; c, neck; d, trunk; e, e, lemnisci.
    1
    0
  • In some (constituting the genus Rhyncocyon) the muzzle is so much prolonged as to resemble a proboscis, whence the name elephant-shrews is sometimes applied to the members of the family.
    1
    0
  • In parasitic bloodsucking forms the mandibles often have the shape of piercing stylets, and are enclosed in a tubular proboscis formed by the union of the upper lip (labrum) with the lower lip (hypostome or paragnatha).
    1
    0
  • A pair of cerebral ganglia lie on the dorsal side of the oesophagus: they innervate the proboscis or head and its tentacular lobes and captacula.
    1
    0
  • This group is characterized by the prolongation of the head into a rostrum or proboscis, at the end of which the mouth, with its appendages, is placed.
    1
    0
  • Fertilization is effected by the male transferring spermatophores into the genital orifice of the female by means of his proboscis.
    1
    0
  • 4) corresponds with the proboscis " of Pterobranchia; the succeeding region, as far as the bases of the tentacles, with the collar; and the post-tentacular region with the metasome.
    1
    0
  • The epistome of the adult Phoronis cannot well be the proboscis since its cavity is continuous with the lophophoral coelom, and because the praeoral hood of Actinotrocha is entirely lost at the metamorphosis.
    1
    0
  • Since the proboscis is a purely larval organ in this genus, it may be supposed that the coelomic space which properly belongs to it fails to develop, but that the praeoral hood itself is none the less the morphological representative of the proboscis.
    1
    0
  • alfalfa plant stems using their proboscis.
    1
    0
  • The plumage is very variable, including red beret, tweed jacket and an orange proboscis.
    1
    0
  • elephantine size but also from the trunk like proboscis possessed by the bulls.
    1
    0
  • eversible proboscis lying dorsal to the gut, which is used to catch prey.
    1
    0
  • Proboscis The adapted mouthparts of various insect groups such as flies and butterflies.
    1
    0
  • Walk around the centers to meet the orangutans, the proboscis monkeys, gibbons and other endemic fauna and exotic flora of Borneo.
    1
    0
  • Test out a mosquito's long proboscis or a white cockatoo's plumage.
    1
    0
  • Yes, each insect has a very long proboscis, designed to reach deep into flowers to the nectar.
    1
    0
  • Head The head holds the eyes and the antennae and the nectar sipping tongue called the proboscis.
    1
    0
  • proboscis recoiled under a rock.
    1
    0
  • Looking down at the palm of her hand, she saw an insect with a long proboscis, oozing blood, her own blood.
    1
    0
  • When touched, the expandable proboscis recoiled under a rock.
    1
    0
  • Parallel evolution even led to the evolution of a short proboscis similar to that found in Tapirus.
    1
    0
  • proboscis monkeys are named for their large, round noses.
    1
    0
  • (ii.) The proboscis (fig.
    1
    0
  • b, Proboscis.
    1
    0
  • e, Ventral edge of proboscis.
    1
    0
  • In the living Cephalodiscus a zooid can crawl by means of its proboscis over the gelatinous processes of the outer side of the coenoecium, a position which it can assume owing to the very great extensibility of the stalk, the proximal suctorial end of which remains attached to the inner surface of some part of the coenoecium (Andersson, 1907).
    1
    0
  • 2, b.c. l) is unpaired, and opens to the exterior by the two proboscis pores (p.p.).
    1
    0
  • b.c l ., Body-cavity of proboscis.
    1
    0
  • In the bud development, the three-segmented condition is extremely conspicuous, and a striking feature is the great relative size of the proboscis (fig.
    1
    0
  • Leeches without biting jaws possess a protrusible proboscis, and generally engulf their prey, as does the horse leech when it attacks earthworms. But some of them are also ectoparasites.
    1
    0
  • The position of this orifice, as we have seen, is at the base of the lip and of the column, so that the insect, if of sufficient size, while bending its head to insert the proboscis into the spur, almost of necessity displaces the pollen-masses.
    1
    0
  • canal sometimes with protrusible proboscis; never with gizzard or oesophageal glands; intestine with caeca as a rule.
    1
    0
  • The inversion of the proboscis is effected directly by the contraction of these a, Siphon.
    1
    0
  • The introversible tube may be completely closed, as in the " proboscis " of Nemertine worms, or it may have a passage in it leading into a non-eversible oesophagus, as in the present case, and in the case of the eversible pharynx of the predatory Chaetopod worms. The diagrams here introduced (fig.
    1
    0
  • Shell ventricose,with elongated aperture, and short spire; proboscis and siphon long;operculum with marginal nucleus.
    1
    0
  • portion, where the proboscis, floating in P.o., Exterior opening its sheath, is attached with it to the through which the muscular tissue of the head (fig.
    1
    0
  • The muscular walls of the rhynchocoel, which by their transverse contractions serve to bring about eversion of the proboscis in the way above traced, are attached to the musculature of the head just in front of the ganglionic commissures (fig.
    1
    0
  • (From Burger.) i, Opening of proboscis; 2, cephalic glands running to frontal organ; 3, dorsal commissure of brain; 4, cerebral organ; 5, upper dorsal nerve; 6, under dorsal nerve; 7, rhynchocoelic blood-vessel; 8, fore-gut; 9, rhynchocoel; to, nerve to proboscis; 11, proboscis; 12, genital sac; 13, genital pore; 14, mid-gut; 15, circular nerves; 16, pore of excretory system; 17, lateral organ; 18, excretory canal; 19, lateral vessel; 20,.
    1
    0
  • Their contraction causes the proboscis to be invaginated into its cavity (fig.
    1
    0
  • But the whole proboscis apparatus can also be, at least partially, withdrawn into the body cavity, and this is effected by two retractor muscles which run from the posterior aspect of the septum to the body wall (fig.
    1
    0
  • It supplies the proboscis with nerves and gives off behind two stout trunks which supply the body (fig.
    1
    0
  • (I) The prolongation of the lower lip or labium into a prominent proboscis, which in the female sex contains the full complement of piercing organs found in blood-sucking Diptera, namely paired mandibles, paired maxillae, a tubular hypopharynx (the common outlet of the salivary glands), and an upper lip or labrum.
    1
    0
  • A fairly satisfactory attempt at grouping the genera has been made by Lutz (1904), who divides the family in the first place into the Euculicidae, with a piercing proboscis (i.e.
    1
    0
  • In appearance tsetse are somewhat narrow-bodied flies, with a prominent proboscis, which projects horizontally in front of the head, and with the wings in the resting position closed flat one over the other like the blades of a pair of scissors (see fig., B).
    1
    0
  • In some genera the oral arms are of great length, and in the suborder Rhizostomeae they undergo concrescence to form a proboscis (fig.
    1
    0
  • The long proboscis of the moth can clearly be seen supping up the juices of a fallen apple.
    1
    0
  • possess a large amount of ep ., Proboscis.
    0
    0
  • In most Heteronemertines it is found to be an elongated slit with corrugated borders; in the Metanemertines it is smaller and rounded; in Malacobdella and Akrostomum it, moreover, serves for the extrusion of the proboscis, which emerges by a separate dorsal opening just inside the mouth.
    0
    0
  • Burger even goes so far as to homologize the proboscis with the Turbellarian " Einige Bemerkungen zur Metamorphose des Pilidium," Archir far Naturgeschichte (1873); L.
    0
    0
  • a, Arrow from proboscis-cavity (pc) passing to left of peri cardium (per) and out through proboscis pore-canal.
    0
    0
  • Prosternum underlying the proboscis.
    0
    0
  • The body is divided into eleven segments and the protrusible proboscis apparently into two, and the cuticle of the central segment is thickened to form three plates, one dorsal and two ventrolateral.
    0
    0
  • The proboscis or "tongue" (fig.
    0
    0
  • Upper margin of the end of the proboscis developed into a distinct finger-like process, much longer than the lower margins, and the whole trunk uniformly tapering and smooth.
    7
    7
  • p.s., Proboscis.
    1
    1
  • From their position in the proboscis the larvae can easily enter the blood of man the next time the mosquito bites (Low, Brit.
    3
    4
  • The manubrium is absent altogether in the fresh-water medusa Limnocnida, in which the diameter of the mouth exceeds half that of the umbrella; on the other hand, the manubrium may attain a great length, owing to the centre of the sub-umbrella with the stomach being drawn into it, as it were, to form a long proboscis, as in Geryonia.
    2
    3
  • The proximal portion forms the retractor muscles of themanubrium, or proboscis, well developed, for example, in Geryonia.
    2
    2
  • The body, representing the hydranth of an ordinary hydroid, has the aboral portion modified into a float, from which hangs down a proboscis bearing the mouth.
    3
    4
  • The parasitic actinula is found attached to the proboscis of the medusa; it thrusts its greatly elongated hypostome into the mouth of the medusa and nourishes itself upon the food in the digestive cavity of its host.
    4
    4
  • A distinctive feature is the position assumed in resting; Culex has a humpbacked attitude, while in Anopheles the proboscis, head and body are in a straight line, and in many species inclined at an angle to the wall, the tail sticking outwards.
    3
    4
  • The other structural characters of the Order may be briefly summarized as: - mouth-parts adapted for piercing and sucking, or for suction alone, and consisting of a proboscis formed of the labium, and enclosing modifications of the other usual parts of the mouth, some of which, however, may be wanting; a thorax fused into a single mass; and legs with five-jointed tarsi.
    3
    4
  • The Pupipara are also termed Eproboscidea (although they actually possess a well-developed and functional proboscis), and by some dipterists the Eproboscidea are regarded as a suborder .and contrasted as such with the rest of the Diptera, which are styled the suborder Proboscidea.
    4
    5
  • - A protrusible proboscis exists, but there are no jaws.
    3
    4
  • As in all such introand e-versible organs, eversion of the Gastropod proboscis is effected by pressure communicated by the muscular body-wall to the liquid contents (blood) of the body-space, accompanied by the relaxation of the muscles which directly pull upon either the sides or the apex of the tubular organ.
    2
    2
  • is a proboscis) - with rare exceptions these forms have a siphonate its whole length, except in Adeorbis and Valvata; in the latter alone it is bipectinate.
    3
    4
  • In the latter a pallial siphon, a welldeveloped proboscis and an unpaired oesophageal gland are always present, in the former they are usually absent.
    2
    2
  • The condition usually spoken of as a " proboscis " appears to be derived from the condition of a simple rostrum (having the mouth at its extremity) by the process of incomplete introversion of that simple rostrum.
    2
    2
  • There is no reason in the actual significance of the word why the term " proboscis " should be applied to an alternately introversible and eversible tube connected with an animal's body, and yet such is a very customary use of the term.
    2
    3
  • Supposing the tube to be completely introverted and to commence its eversion, we then find that eversion may take place, either by a forward movement of the side of the tube near its attached base, as in the proboscis of the Nemertine worms, the pharynx of Chaetopods and the eye-tentacle of Gastropods, or by a forward movement of the inverted apex of the tube, as in the proboscis of the Rhabdocoel Planarians, and in that of Gastropods here under consideration.
    3
    4
  • The acrembolic proboscis or frontal introvert of the Nemertine worms has a complete range.
    3
    4
  • So too the acrembolic eye-tentacle of the snail has a complete range of movement, and also the pleurembolic proboscis of the Rhabdocoel prostoma.
    2
    2
  • B, The same, partially everted by eversion of the sides, as in the Nemertine proboscis and Gastropod eye-tentacle = pleurecbolic.
    5
    5
  • One of the best examples of the introversible mouth-cylinder or proboscis which can be found is that of the common whelk (Buccinum undatum) and its immediate allies.
    4
    5
  • 23 the proboscis is seen in an everted state; it is only so carried when feeding, being withdrawn when the animal is at rest.
    4
    5
  • - A, Triton variegation, to show the proboscis or buccal introvert (e) in a state of eversion.
    4
    4
  • Shell turriculated, with elongated spire; proboscis short; siphon rudimentary.
    4
    4
  • They have a well-developed proboscis which is used as a suctorial organ; some are abyssal, but the majority are either commensals or parasites of Echinoderms.
    4
    4
  • Mucronalia, foot reduced, but still operculate, eyes present, animal fixed by its very long proboscis which is deeply buried in the tissues of an Echinoderm, no pseudopallium.
    2
    2
  • No buccal appendages or suckers; a very long evaginable proboscis; a quadriradiate terminal branchia.
    3
    3
  • NEMERTINA, or Nemerteans (Nemertea), a subdivision of worms,' characterized by the ciliation of the skin, the presence of a retractile proboscis, the simple arrangement of the generative apparatus, and in certain cases by a peculiar pelagic larval stage to which the name " pilidium " has been given.
    2
    3
  • Protonemertini, in which there are two layers of dermal muscles, external circular and internal longitudinal; the nervous system lies external to the circular muscles; the mouth lies behind the level of the brain; the proboscis has no stylet; there is no caecum to the intestine.
    1
    2
  • Metanemertini, in which the nervous system lies inside the dermal muscles in the parenchyma; the mouth lies in front of the level of the brain; the proboscis as a ru'e bears stylets; the intestine nearly always has a caecum.
    3
    4
  • pr, Proboscis.
    1
    1
  • p.o., Opening for proboscis.
    1
    1
  • with the mouth into a single exterior opening), there is a terminal opening, the rhynchostome (subterminal in Valencinia), at the foremost tip of the body, out of which the proboscis is seen shooting backwards and forwards, sometimes with so much force that both its interior attachments are severed and it is entirely expelled from the body.
    2
    3
  • It then often retains its vitality for a long time, apparently crawling as if it were itself a worm, a phenomenon which is at least partially explained by the extraordinary development of nervous tissue, equally distributed all through the walls of the proboscis, and either united into numerous longitudinal nerve-stems (Drepanophorus, Amphiporus) or spread out into a uniform and comparatively thick layer (Cerebratulus, sp.).
    4
    4
  • This very effective and elaborate innervation, which has been directly traced to the brain, whence strong nerves (generally two) enter the proboscis, renders it exceedingly probable that the most important functions of the proboscis are of a sensiferous, tactile nature.
    4
    5
  • In Nemertines the everted proboscis is retracted in the same way as the tip of a glove finger would be if it were pulled backwards by a thread situated in the axis and attached to the tip. The comparison may be carried still further.
    4
    5
  • The central thread just alluded to is represented in the Nemertean proboscis by that portion which is never everted, and the tip of the glove by the boundary between the evertible and non-evertible portion of the proboscis - a boundary which in the Metanemertini is marked by the presence of a pointed or serrated stylet.
    4
    5
  • _This stylet is thus situated terminally when the proboscis has reached its maximum eversion.
    2
    3
  • This aggressive character has a different aspect in several genera which are destitute of a central stylet, but in which the surface that is turned outwards upon eversion of the proboscis is largely pro- P. vided with nematocysts, sending the urticating rods of different sizes in all directions.
    2
    2
  • The comparison with the glove-finger is in so far insufficient as the greater portion of the non-evertible half of the proboscis is also hollow and clothed by glandular walls.
    3
    3
  • This retractor-muscle, indeed, serves to pull back with great rapidity the extruded proboscis, and is aided in its action by the musculature of the head.
    1
    2
  • proboscis is everted Partial extrusion lessening the resistor rhynchostome.
    2
    2
  • It is worthy of notice that in those Nemertines which make a very free use of their proboscis, and in which it is seen to be continually protruded and retracted, the walls of the proboscidian sheath are enormously muscular.
    1
    2
  • The proboscis, which is thus an eminently muscular organ, is composed of two or three, sometimes powerful, layers of muscles - one of longitudinal and one or two of circular fibres.
    6
    6
  • At the circular insertion of the proboscis in front of the brain the muscular fibres belonging to the anterior extremity of the body and those connected with the proboscis are very intimately interwoven, forming a strong attachment.
    2
    3
  • The proboscis broken off and expelled is generally reproduced, the posterior ribbon-like end of this reproduced portion again fusing with the walls of the sheath.
    3
    4
  • P, Proboscis.
    1
    1
  • In the female of Culex the palpi are much shorter than the proboscis; in Anopheles they are of the same length.
    3
    5
  • Heteronemertini, in which the dermal musculature is in three layers, an external longitudinal, a middle circular, an internal longitudinal; the nervous system lies between the first and second of these layers; the outer layer of longitudinal muscles is a new development; there is no intestinal caecum; no stylets on the proboscis and the mouth is behind the level of the brain.
    5
    7
  • - Proboscis and Proboscidian Sheath.
    2
    4
  • 2), which is attached to the wall of the space, or rhynchocoel, in which the proboscis moves about.
    2
    4