. A textbook of invertebrate morphology [microform]. Invertebrates; Morphology (Animals); Invertébrés; Morphologie (Animaux). epoda, and rst thoracic 5 usually a ig, some iu- ptus, while 'ius, Calamis TYPE CHUSTACEA. 397 lUnFACE ( .^curriug in -supply for aud, lead a jhamlxM' of f forms arc in dirteroiit , becoiniiii,' brilHaiitly- iH, ])arasitic rnigh essen- tially parasitic, still retain more or less perfectly the segmen- tation and general appearance of free-swimming forms, the modifications which they have undergone affecting principally the antennae, which are modified for purposes
. A textbook of invertebrate morphology [microform]. Invertebrates; Morphology (Animals); Invertébrés; Morphologie (Animaux). epoda, and rst thoracic 5 usually a ig, some iu- ptus, while 'ius, Calamis TYPE CHUSTACEA. 397 lUnFACE ( .^curriug in -supply for aud, lead a jhamlxM' of f forms arc in dirteroiit , becoiniiii,' brilHaiitly- iH, ])arasitic rnigh essen- tially parasitic, still retain more or less perfectly the segmen- tation and general appearance of free-swimming forms, the modifications which they have undergone affecting principally the antennae, which are modified for purposes of adhesion to the host, the mandibles, which are piercing organs, and in some cases the maxillre, which may, like the antennjB, become hook- like. Frequently, however, the body assumes aberrant forms, as in Philichthys (Fig. 178, A), aud the segmentation may en- tirely disappear, as in Penella, Lerncea, Chondracanthus, Achtheres (Fig. 178, /?), and Anchorella, these last two forms presenting a peculiar modification of ...le second maxilhe in the females, the two appendages fusing at their tips to form a chitinous adhesive disk which serves as an organ of adhesion. In the majority of these forms, as already noted, the thoracic appendages may become more or less rudimentary; indeed even in the less modified forms, such as , the appendages of the fifth thora- ic segment may be wanting. nix 3. Suborder Branclnura. In the Branchiura the cephalic and thoracic seg- ments are fused together to form a shield-shaped ce})halo- tliorax, while the abdomen is small and divided into two platelike halves which have a rich blood-suppl}', appar- ^^^- '^"^^â âArpnlim foliaceua (after ontly serving resi)iratory ])ur-. âresiive glaud. contain the testes. wa; = second muxilla. The basal joint of the an- '"'= '*>'''⢠tennules (Fig. i7(>, at') is devel- ' " ^''"''⢠oped into a strong hooked process, aud the mandibles and. 12 -SI tirst maxillo), which a
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishernewyo, bookyear1896
