. Elementary text-book of zoology. Zoology. TELEOSTKI. 1(17 fibres of the other without forming a chiasina. The gills are usually comb-shaped, and, as in the Ganoids, lie freely in a branchial cavity under a branchial opercukuu, to which is added a a branchiostegal membrane, supported by branchiostegal rays. The skeleton is char- acterised by the well separated, usually bony vertebra?, and by the b}ny skull, beneath which remains of the primitive cartilaginous cranium often persist. The skin is only rarely naked or apparently \\ithout scales. In such cases the scales are very small and do not
. Elementary text-book of zoology. Zoology. TELEOSTKI. 1(17 fibres of the other without forming a chiasina. The gills are usually comb-shaped, and, as in the Ganoids, lie freely in a branchial cavity under a branchial opercukuu, to which is added a a branchiostegal membrane, supported by branchiostegal rays. The skeleton is char- acterised by the well separated, usually bony vertebra?, and by the b}ny skull, beneath which remains of the primitive cartilaginous cranium often persist. The skin is only rarely naked or apparently \\ithout scales. In such cases the scales are very small and do not project from the surface ; more frequently bony plates and scutes are present in it, especially behind the head. As a rule the skin is covered by cycloid or ctenoid scales which overlap one another. The urinary and genital organs open behind the anus either separately or by a common aperture on a urogeiiital papilla. [The kidney is dilated in front to form a head-kidney, which, however, is in the adult, sometimes if not always, largely composed of a tissue resembling lymphatic tissue (Balfour). The generative ducts are continuous with the investments of the generative glands in both sexes, and in the male there is no connection between the testis and the kidney.] Only a few Teleosteans ai-e viviparous; they almost all lay small eggs in enormous numbers in protected places. Sub-order 1. Lophobranchii. Teleo- steaiis with armoured skin, elongated tubular snout which is without teeth. The gills are in the form of tufts and the gill slits are very Br FIG. 609.—Male of Hippocampus with the brood-poucli (Brt). Fain. Pegasidae. The body is flattened : pectoral fins large, spread out like wings; pelvic tins small. Fi'i/uxus roJrt/tx L., KasI Indies. Fam. Syngnathidae. The body is cylindrical or laterally compressed. The gill openings narrow, and pectoral tins small ; males with brood-pouches (fig. 609). tii/nf/natJiHx tii-itx L., Pipe-fish : Hippocampux iintiyuiirinii Leach.
Size: 1068px × 2340px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectzoology, bookyear1884
