Elementary text-book of zoology (1884) Elementary text-book of zoology elementarytextbo0101clau Year: 1884 PHYLLOPODA. strongest. In other cases a pair of tin-like appendages are present constituting the caudal fork (Branchipus). Appendages.—On the head there are two pairs of antenna?, which however, in the adult animal, may be rudimentary or peculiarly modified. The anterior antenna? are small, and bear the delicate olfactory hairs. The posterior antennae frequently have the form of large biramous swimming appendages, but in the male may also have a prehensile function, , Branchipus. In
Elementary text-book of zoology (1884) Elementary text-book of zoology elementarytextbo0101clau Year: 1884 PHYLLOPODA. strongest. In other cases a pair of tin-like appendages are present constituting the caudal fork (Branchipus). Appendages.—On the head there are two pairs of antenna?, which however, in the adult animal, may be rudimentary or peculiarly modified. The anterior antenna? are small, and bear the delicate olfactory hairs. The posterior antennae frequently have the form of large biramous swimming appendages, but in the male may also have a prehensile function, , Branchipus. In other cases (Apus) they are rudi- mentary and may even be entirely absent. Two large mandibles are always present beneath the well developed upper lip; they possess a toothed, biting edge, and in the fully developed condition are invariably destitute of palps. The mandibles are followed by one or two pairs of slightly developed maxilla?. A kind of under- lip is in many cases present, in the form of two promi- nences behind the mandibles. The legs, which are placed on the thorax, are usually very numerous, and are smaller towards the poste- rior end of the body. They are lobed, leaf-like, bira- mous structures, and func- tion as swimming feet; they also assist in procuring food. They consist of the following parts: a short basal portion, which is usually provided with a masticatory process and is followed by a long foliaceous stem with seta? on its inner edge ; this is continued into the niultilobed internal branch [endopodite] of the biramous limb, while it bears 011 its outer side the external ramus [exopodite] with marginal seta?, and nearer 27 FIG. 333.—Male of Sruncliipits gtnnntiJ'm. Kg, Heart or dorsal vessel with a pair of slit-like openings iu each segment; D, intestine; M, mandible; Sd, shell gland; B>; branchial appendages of the eleven pairs of legs ; T, testis.
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