The labial tentacles or palps of Anodonta (n, o in fig.
The labial palps are direct continuations of the lips.
- One row of branchial filaments is directed dorsally, the other ventrally; the mantle has a long posteroventral suture and a single posterior aperture; the labial palps of each side are fused together; shell elongate; hinge without teeth; periostracum thick.
The maxillary palps have usually three, the labial either two or four segments.
The palps, both maxillary and labial, have two segments.
A, Beetle; b, head of beetle with feelers and palps; c, larva; d, pupa.
The mandibles are strong, adapted for biting the vegetable substances on which these beetles feed, and the palps of the second maxillae have three segments.
The ventraPscleriteof the head-skeleton (gula), well developed in most families of beetles, is absent among the Rhynchophora, while the palps of the maxillae are much reduced.
39) have jointed, flexible palps, feelers - often of excessive length - with a short basal segment, and the three terminal segments forming a club, and, in some genera, larvae with legs.
- " Errant" Polychaetes with well-marked prostomium possessing tentacles and palps with evident and locomotor parapodia, supported (with few exceptions) by strong spines, the aciculi; muscular pharynx usually armed with jaws; septa and nephridia regularly metameric and similar throughout body; free living and predaceous.
Parapod.ia hardly projecting; palps of prosomium forming branched gills; no pharynx or eversible buccal region; no septa in thorax, septa in abdomen regularly disposed.
Head with two long labial palps; shell ovoid; operculum horny, semicircular, carinated.
They never bear segmented limbs (palps) and only exceptionally (as in the chafers) is the skeleton composed of more than one sclerite.
1, C, sm, m - jointed on to the submentum, while the galeae, laciniae and palps remain distinct.
In specialized biting insects, such as beetles (Coleo C ptera), the labium tends to become a hard transverse plate bearing the pair of palps, a median structure - known as the ligula - formed of the conjoined laciniae, and a pair of small rounded processes - the reduced galeae - often called the " paraglossae," a term better avoided since it has been applied also to the maxillulae of Aptera, entirety different structures.
Mandibles absent in imago, very exceptionally present in pupa; first maxillae nearly always without laciniae and often without palps, or only with vestigial palps, their galeae elongated and grooved inwardly so as to form a sucking trunk.
Mandibles rarely present, adapted for piercing; first maxillae with palps; second maxillae forming with hypopharynx a suctorial proboscis.
The first pair of limbs is often chelate or prehensile, rarely antenniform; whilst the second, third and fourth may also be chelate, or may be simple palps or walking legs.
46) is atrophied, or whether, if present, it has the form of a pair of tactile palps or of minute chelae.
The segmentation of the prosoma and the form of the appendages bear a homoplastic similarity to the head, pro-, meso-, and meta-thorax of a Hexapod with mandibles, maxillary palps and three pairs of walking legs; while the opistho io i e d c b o a S' S" 2 I VT V S IV III II I Opisthosoma Prosoma FIG.
Vestigial palps have been described in various species of Hemiptera, but the true nature of these structures is doubtful.
The palps are really derived from part of the velar area of the larva.
- Labial palps free, very broad, and provided with a posterior appendage; branchial filaments transverse; shell has an angular dorsal border; mantle open along its whole border.
Lucinidae.-Labial palps very small; gills without an external plate.
Labial palps very large.
Tellinidae.-External gill-plate directed upwards; siphons separate and elongated; foot with byssus; palps very large; ligament external.
The tenth abdominal segment carries a pair of jointed cerci which are often elongate, and the feelers are always long, while the jaws are usually feeble and membranous, though the typical parts of a mandibulate mouth are present - mandibles, maxillae with inner and outer lobes and palps, and second maxillae (labium) whose lacinae are not fused to form a ligula.
They are abundantly distinct from the Neuroptera and Mecaptera, through the absence of mandibles in the imago, the maxillae - both pairs of which possess the typical inner and outer lobes and jointed palps - forming a suctorial apparatus.
In all Trichoptera the maxillary palps of the female are fivesegmented.
The family Phryganeidae have males with foursegmented hairy palps; the larvae inhabit stagnant water and make cases of vegetable fragments.
The males of the Sericostomatidae have two or three segmented palps; their larvae inhabit running water and make cases of grains of sand, or of small stones.
In the Leptoceridae, Hydropsychidae, Rhyacophilidae and Hydroptilidae the palps of the males have five segments like those of the females.
"Palps" or "feelers" of sting.
(Fritz Miller.) and exopodite persisting only as sensory " palps " or disappearing altogether.
These may be formed by the modification of almost any of the appendages, often the antennules or antennae or some of the thoracic limbs, or even the mandibular palps (some Ostracoda).
All the cephalic appendages are much reduced, the mandibles have no palps, and the maxillulae are vestigial.
In those Copepods in which the palps of the mandibles as well as the antennae are biramous and natatory, the first three pairs of appendages retain throughout life, with little modification, the shape and function which they have in the nauplius stage, and must, in all likelihood, be regarded as approximating to those of the primitive Crustacea.
The palps are very short and conical as a rule.
In Apus, as the figure shows, there are four of these " antenna-like " palps or filaments on the first thoracic limb.
The mandibular somite bears a pair of gnathobasic hemignaths without rami or palps, and is followed by two jaw-bearing somites (maxillary and labial).