. A manual of zoology. 402 MANUAL OF ZOOLOGY number of other bones in the wall of the mouth. In most of the Teleostei the maxilla is devoid of teeth, and does not enter into the upper boundary of the mouth opening. In the great majority the teeth are small and very numerous, adapted for preventing the struggling prey from slipping out of the mouth, but quite unfitted for either tearing or crush- ing ; but in many instances teeth are comparatively large and few in number, and in some (Fig. 242) there is a marked differentiation of the teeth, those in front of the jaws being. Fig. 242. — Premaxi
. A manual of zoology. 402 MANUAL OF ZOOLOGY number of other bones in the wall of the mouth. In most of the Teleostei the maxilla is devoid of teeth, and does not enter into the upper boundary of the mouth opening. In the great majority the teeth are small and very numerous, adapted for preventing the struggling prey from slipping out of the mouth, but quite unfitted for either tearing or crush- ing ; but in many instances teeth are comparatively large and few in number, and in some (Fig. 242) there is a marked differentiation of the teeth, those in front of the jaws being. Fig. 242. — Premaxillae of Sargus, showing teeth. (After Owen .) pointed or chisel-shaped, and adapted for seizing or cutting, while the back teeth have rounded surfaces adapted for crushing. The teeth may be either simply embedded in the mucous membrane so as to be detached when the bones are macerated or boiled, or they may be implanted in the sockets of the bone or ankylosed to it. Their succession is perpetual, , injured or worn-out teeth are replaced at all ages. The Ganoids have a spiral valve in the intestine ; this is absent in the Teleostei. Cceca (the pyloric cceca) are commonly developed at the junction of the stomach and small intestine. The anus is always distinct from, and in front of, the urogenital apparatus, there being no cloaca such as occurs in Elasmobranchs. The gills are usually. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Parker, T. Jeffery (Thomas Jeffery), 1850-1897; Haswell, William A. (William Aitcheson), 1854-1925. New York, The Macmillan Company; London, Macmillan & Co. ,Ltd.
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