. A manual of zoology. XII PHYLUM CHORDATA 395 sion of an operculum or gill-cover, by the absence of a cloaca, by having the primary skull and shoulder-girdle complicated by the addition of membrane-bones, and by possessing bony instead of horn-like fin-rays. A typical Teleostomian, such as a trout (Fig. 235)' or a herring, has a long compressed body nearly half of which is formed by the tail, pointed anterior and posterior ends, a large vertical tail-fin, a head of moderate size, and a terminal mouth. Such a form is eminently fitted for progression through the water. But from this characteris
. A manual of zoology. XII PHYLUM CHORDATA 395 sion of an operculum or gill-cover, by the absence of a cloaca, by having the primary skull and shoulder-girdle complicated by the addition of membrane-bones, and by possessing bony instead of horn-like fin-rays. A typical Teleostomian, such as a trout (Fig. 235)' or a herring, has a long compressed body nearly half of which is formed by the tail, pointed anterior and posterior ends, a large vertical tail-fin, a head of moderate size, and a terminal mouth. Such a form is eminently fitted for progression through the water. But from this characteristic fish form. Fig. 235.—Salmo fario. a. I, adipose lobe of pelvic fin; an, anus; c. /, caudal fin; I, first dorsal; d /. 2, second dorsal or adipose fin; /. /, lateral line; op, operculum; pet. /, pectoral fin ; pv. f, pelvic fin ; v. ft ventral fin. (After JardineJ there are many striking deviations. The body may be greatly elongated and almost cylindrical, as in the eels; or of great length and strongly flattened from side to side, as in the ribbon-fishes; or the head may be of immense pro- portional size and strongly depressed, as in certain shore- fishes, such as the fishing-frog ; or, as in the beautiful reef- fishes, the whole body may be as high as it is long. The mouth sometimes has a ventral position, as in the Elasmo- branchs, with the snout prolonged over it; this is the case, 1 Our common brook trout in the northeastern states is Salmo 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.
Size: 2720px × 919px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublishernewyo, bookyear1900
