The introverted rostrum of the Pectinibranch Gastropods presents in contrast to these a limited range of FIG.
The head is seen in front resting on the foot and carrying a median non-retractile snout or rostrum, and a pair of cephalic tentacles at the base of each of which is an eye.
Homoptera: Rostrum in contact with haunches of fore-legs.
Rostrum free, not supported by either the prosternum or the basal segments of the appendages.
Taking as our type the head of a cicad, we find a jointed rostrum or beak (figs.
They fly about from July till October, living upon the sap of the vine, which is sucked up by the rostrum from the leaves or buds.
- Note the simple snout or rostrum not introverted as a " proboscis."
Within the groove of the rostrum two pairs of slender piercers - often barbed at the tip - work to and fro.
The point of the rostrum is pressed against the surface to be pierced; then the stylets come into play and the fluid food is believed to pass into the mouth by capillary attraction.
Under- (Radicola) of Phylloxera, with proneath, between the legs, lies the boscis inserted into tissue of root rostrum, which reaches back to of vine.
The name of "pink shrimp" is given to Pandalus montagui or annulicornis, which turns red on boiling and which resembles in form the larger "prawns," having a long rostrum or beak, saw-edged above and below.
The bivalved carapace has a jointed rostrum, and covers only the front part of the body, to which it is only attached quite in front, the valve-like sides being under control of an adductor muscle.
This becomes divided into two, the right half forming the cavity of the rostrum, while the left acquires an opening to the exterior, and forms the praeoral pit of the larva, which subsequently gives rise to special ciliated tracts in the vestibule of the mouth mentioned above.
Usually the sides of the carapace are strangely produced into a mock rostrum in front of the ocular lobe, be it oculiferous or not.
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.
The basal portion of the antennae frequently lies in a depression at the side of the rostrum, and this gives the antennae the appearance of emerging half-way along the rostrum.
Its rostrum is unusually long, being five-sixths of the body length in the female, and slightly shorter in the male.
When the nuts are about half-grown, the female bores, with its rostrum, a minute hole in the still comparatively soft nut-shell, and deposits an egg within the nut.
The capitulum, with its associated structures, is sometimes called the rostrum, whereas sometimes the term rostrum is restricted to the hypostome alone.
A, Rostrum or hypostome; b, b, Palpi; c, Genital aperture; d, Anal orifice; e, e, Ventral surface of capitulum; g, Sternum; 1 -7, segments of leg.
Rbs, Rostrum of basi-sphenoid.
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.
(From Owen.) cylinder, but have a simple non-introversible rostrum, as it has been termed, which is also the condition presented by the mouth-bearing region in nearly all other Gastropoda.
Ia, frons; b, clypeus (the pointed labrum beneath it); II, mandible; III, first maxilla; (a, base; b, sheath; c, piercer), III', inner view of sheath; IV, second maxillae forming rostrum (b, mentum; c, ligula).
Heteroptera: Rostrum not in contact with haunches of fore-legs.
The sternum has no keel, and ossifies from lateral and paired centres only; the axes of the scapula and cora.coid have the same general direction; certain of the cranial bones have characters very unlike those possessed by the next order - the vomer, for example, being broad posteriorly and generally intervening between the basisphenoidal rostrum and the palatals and pterygoids; the barbs of the feathers are disconnected; there is no syrinx or inferior larynx; and the diaphragm is better developed than in other birds.'
In them the vomer, however variable, always tapers to a point anteriorly, while behind it includes the basisphenoidal rostrum between the palatals; but neither these nor the pterygoids are borne by its posterior divergent ends.
The irritation is caused by the rostrum of the insect being inserted into the skin, from which the blood is rapidly pumped up. A third human louse, known as the crab-louse (Phthirius pubis) is found amongst the hairs on other parts of the body, particularly those of the pubic region, but probably never on the head.
The immense family of the Curculionidae includes members which differ greatly from one another in size, colour, and appearance; even the rostrum, the most striking common characteristic, varies greatly.
The insect is fixed by this rostrum, which is inserted into the root of the vine for the purpose of sucking the sap. The abdomen consists of seven segments, and these as well as the anterior segments bear four rows of small tubercles on their dorsal surface.
A scaffold, connected by a wooden bridge with the magistrates' rostrum, had been erected on the spot where the piles of the m.
The vomer is broad, abruptly truncated in front, and deeply cleft behind, so as to embrace the rostrum of the sphenoid; the palatals have produced postero-external angles; the maxillo-palatals are slender at their origin, and extend obliquely inwards and forwards over the palatals, ending beneath the vomer in expanded extremities, not united either with one another or with the vomer, nor does the latter unite with the nasal septum, though that is frequently ossified.
Between these, resting vertically upon the rostrum, appears the vomer; very variable in shape and size, often reduced to a mere trace, as in the Galli, or even absent, broken up into a pair of tiny splints in Pici.