OCR Text |
Show 1 APPfcNWX C- REPTILES* 865 temporal region is very much developed and projects over the auditory aperture, and is provided along its projecting margin with spines, or conical plates, the largest of which is most approximated to the occiput. The eyes seem as if situated in the middle of a groove extending from the snout to the occiput, on account of thfe projection of the superciliary ridge- arid temporal region. ' The loiter jaw is generally Ordered with a row . or- two of large plates, which vary in structure and shape according to the species, and furnish good discriminating characters between them. The snout is either truncated or actlte. The nostrils: are conspicuous, and situated near the extremity of the sntrat, either within the inner margin of the superciliary ridge, or on its direct prolongation. The upper surface of the head and sides not occupied fey the spines or tuberculous knobs, are covered with small pblygonal plates^ varying in size according to the area over whifch they extend. The surface of these plates is rtagose, wrinkled or keeled, as is also the surface of the spines themselves. They are exceedingly sfaall in advance and behind the orbits. The whole surface of the eyelids is covered with minute scales of a granular appearance; the margin of the eyelid itself is ornamented with a double row of suB-quadrangular plates, a little larger than the granules of its surface. The lower part of the' head from the chin to the breast is covered with small'scales, characteristic in each species.' The neck is generally very short, appearing as if contracted, the Result of Which contraction Would be the presence of several folds* of the skin, concealing the auditory apertures in conjunction with the temporal projection of the' head. - ' The scales on the upper surface of the body are vcfry irregular in size and shap$ v, on the neck, above and below, , on the pits, along the sides of the back, and on the groins, they Assume a granular appearance, while along the middle of the b& ck and on the tail they appear lijc^ thin lamellae, very irregular still, and cari-nated or subparinated. All over the back, sides, tail, and hind legs, there are large, irregularly pyramidal scales, with an acute point and a wrinkled or carinated surface. The margins of the abdomen exhib. it one or two horizontal rows of these pyramidal. but soft scales, bent backward, extending from the fore legs to the Bind ones; The. species in which the Scales of the back are the largest; is Phr. corotoatum, which strikes every one by its rough appearance ; while those in which the scales are the least developed are Phr. pUtyrhinos and Phr. modeStum, whose external appearance |