. Outlines of zoology. Zoology. Fig. 220.—Lateral view of dog-fish [Scyllium catulus). Note ventral mouth with naso-buccal groove, heterocercal tail, and unpaired fins, Gill-slits; pc, pectoral fins; pv., pelvic fins. on each side; the upper jaw is fused to the cartilaginous skull; the skin is naked; the anus, the Mullerian and urinary ducts, open separately. Otherwise the Holocephali resemble Elasmobranchs, and may be regarded as a sub-order. In some respects, however, in the structure of the skull, they suggest Dipnoi, and in the connection it is interesting to notice that there is
. Outlines of zoology. Zoology. Fig. 220.—Lateral view of dog-fish [Scyllium catulus). Note ventral mouth with naso-buccal groove, heterocercal tail, and unpaired fins, Gill-slits; pc, pectoral fins; pv., pelvic fins. on each side; the upper jaw is fused to the cartilaginous skull; the skin is naked; the anus, the Mullerian and urinary ducts, open separately. Otherwise the Holocephali resemble Elasmobranchs, and may be regarded as a sub-order. In some respects, however, in the structure of the skull, they suggest Dipnoi, and in the connection it is interesting to notice that there is an auricular septum in Fig. 221.—Outline ot Acanthodes suicatus.—After Traquair. p., Pectoral fins ; v., ventrals ; a., anal; d., dorsal. Teeth (of Ptyctodus, Rhynchodus, etc.), which have been referred to Chirmeroids, occur in Devonian rocks, and some at least of the detached spines of Carboniferous age may have belonged to fishes of this order or sub-order. Undoubted Mesozoic Chimseroids are Squaloraja, Myriacanthus, Chimceropsis, Ischyodus, etc., while others, including the recent genus Chimtzra, are found in strata of Tertiary age. The other recent genus, Callorhynchus, is also represented by a Cretaceous species, C. 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 Thomson, J. Arthur (John Arthur), 1861-1933. Edinburgh, Glasgow and London, H. Frowde and Hodder & Stoughton
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Keywords: ., bookauthorth, bookcentury1800, bookdecade1890, booksubjectzoology
