S A U R I A. 



than in S. undulatus, though, in their general form and disposition, 

 they are alike. 



The most prominent difference, however, between the present 

 species and S. undulatus, consists in the scales, both dorsal and abdo- 

 minal, and which are a good deal larger, as exhibited by figs. 13 & 20. 

 The dorsal ones are more conspicuously keeled, giving to the animal 

 a much rougher appearance, whilst on the abdomen, they are not 

 quite so deeply notched or pointed, making them to appear smoother. 

 The scales under the hind limbs are but very slightly keeled, if at 

 all, except on the sole of the feet, which again appear very rough. 

 The two large postanal shields, that may be seen on fig. 9, and which 

 are a characteristic of the male sex, when compared to those in figs. 

 2 & 16, of the same plate, will show corresponding differences. 



The coloration we will not attempt to describe from the specimens 

 preserved in alcohol. Judging of it by the faint traces that may still 

 be observed, it must have been very similar in its pattern to that of 

 S. undulatus. The blue abdominal patches are wider apart. 



LOG. California and Oregon, west of the Rocky Mountains. 



Plate XIX, fig. 8, represents the profile of the male sex of Scelopo- 

 rus occidentalis, size of life. 



Fig. 9, is an under view of the same individual. 



Fig. 10, the head, viewed from above ; 



Fig. 11, a front view of the head. 



Fig. 12, the right hand, seen from above. 



Fig. 13, a group of dorsal scales ; 



Fig. 14, a group of abdominal scales. 



Figs. 10-14, being somewhat magnified, for the purpose of repre- 

 senting more distinctly all these parts. 



3. SCELOPORDS FRONT ALIS, B. & G. 

 (Plate XIX, figs. 1-7.) 



CHAR. SPEC. Scuto verticis quam anteparietalem majori ; scutis post- 

 parietalibus in duo, paria ordinatis, quam anteparietalem tninoribus, 

 pare anteriori majori. Latero-occipitalium pare uno. Scuto occipitali 



