OCR Text |
Show 840 APPENDIX 0.- KEPTILES. distinct; the anal ones are wanting. The tail is cylindrical, longer than the body and head together. The genus Crctaphytus differs from Holbrookia in having external auditory apertures, teeth on the pterygoids, and- bnt a minute occipital plate. The shape of the head is. likewise more elongated and pointed in front. CBQTAPHYTUS WISLIZENH, Baird and Girsrd. " PLATlin. SPEC: CHAE.- Head proportionally narrow and elongated. Cephalic plates and scales on- the bac* Yery small. Yellowish brown; spotted all over with sMall patches of deeper Iprown or black. ' > C. wulizenii has the sanie general form and appearance as C. eollarUy exhibiting the same contracted neck and fold under the throat, the same compact body, the same cylindrical and elongated tail* and the same shape and proportions of locomotive members and . terminating toes. The differences by which the two are distinguished, although of a comparatively minor character,, are readily appreciable when both are directly compared. Thus the head of C.' wisHzeniiis proportionally more elongated and narrower than that of < 7. collarU. The smaH and potygonal plates which cover its upper surface and sides are smaller, as well as those of the lip of the lower jaw. The scales of the back are likewise smaller, and those of the belly larger. The tail is somewhat longer, and its scales larger in C. collarU; these are ftubvertioillated in both species, and subcarinated from the middle of the back toward its extremity. The pores of the lower surface of the thighs are more conspicuous in C. collaris, indepepdently of the fact that they are generally less so in the female than in the male, of the same species. Immediately behind the vent, at the origin of the tpil, there exists, in the male, a row of large scales more uniform in C. collaru than, in C. mslizenii. The specimen figured on our plate III. being a female, these anal plates are not to be seen in fig. 4. In the colours of, the body distinctive marks will at once be found. C. eoUari$ possesses on the sides of i& e neck'a double band of black bordered with white, which does not exist in O. wi$- lizeftii. The upper surface of the body* of the former is scattered all over with small yellow dots, which indeed are found in the latter, but are much smaller and more numerous, having in' addition, intermixed with them, irregular roundish brown spots, extending |