. Elementary text-book of zoology, general part and special part: protozoa to insecta. Animals. PUTLLOPODA. 417 strongest. In other cases a pair of fin-like appendages are presenl constituting the caudal fork [Branchijms). Appendages.—On the head there are two pairs of antennae, whicl* however, in the adult animal, may be rudimentary or peculiarly modified. The anterior antennje are small, and bear the delicate olfactory hairs. The posterior antennre frequently have the form of large biramous swimming appendages, but in the male may also have a prehensile function, , Branch'qnts. In other
. Elementary text-book of zoology, general part and special part: protozoa to insecta. Animals. PUTLLOPODA. 417 strongest. In other cases a pair of fin-like appendages are presenl constituting the caudal fork [Branchijms). Appendages.—On the head there are two pairs of antennae, whicl* however, in the adult animal, may be rudimentary or peculiarly modified. The anterior antennje are small, and bear the delicate olfactory hairs. The posterior antennre frequently have the form of large biramous swimming appendages, but in the male may also have a prehensile function, , Branch'qnts. In other cases {Ajyii^) they are rudi- mentary and may even be enirely 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 maxillfe. 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 setse on its inner edge ; this is continued into the multilobed internal branch [endopodite] of the biramous limb, while it bears on its outer de the external ramus [exopodite] with marginal sette, and nearer. Fig. 333.—Male of Branchipus sfagnalis. Eg, Heart or dorsal vessel with a pair of slit-like openings in each segment; D, intestine; M, mandible; Sd, shell gland; Br, branchial appendages of the eleven pairs of legs ; T, Please note that these images are extracted from scanned page images that may have been digitally enhanced for reada
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectanimals, bookyear1892
