48 



CALIFORNIA ACADEMY OF SCIENCES. 



when seen from above but pointed in profile. The head 

 is covered with irregular plates, the largest of which is 

 the interparietal. The labials are produced laterally and 

 are strongly imbricate. The ear-opening is large. The 

 dorsal scales are very small and nearly uniform. There 

 are no fringes of movable scales on the digits. Long 

 series of femoral pores are present. There are two or 

 more transverse gular folds. Males have enlarged post- 

 anal plates. 



8. — Callisaurus ventralis (Hallowell). Gridiron-tailed 

 Lizard. 



Homalosaurus ventralis Hallow., Proc. Acad. Nat. Sci. Phila., VI, 

 1852, p. 179 (type locality New Mexico); and Sitgr. Zuui & 

 Colorado Kivers, 1853, p. 117, pi. 6. 



Description. — Head rather short and low, with well 

 developed canthus rostralis. Nostrils large, opening 

 on upper surface of snout. Supraocular regions covered 

 with small plates and separated from each other by one 



or two rows of slightly larger plates. Upper head plates 

 (except interparietal) small and irregular, largest on 

 frontal and prefrontal regions, everywhere smooth and 

 flat. Several subocular plates, middle one very long and 

 strongly keeled. Superciliaries rather small, but strongly 



