EXPLANATION OF THE PLATES. 



PLATE I. 



Emys nigra, Hallow. — Half natural size. 



PLATE IL 



Crotalus ornatus, Hallow. 



a. Side view of liead. 



Crotalus lecontii, Hallow, 

 o. Head from above. 



PLATE in. 



PLATE IV 



Figure 1. Crotalus cerastes, Hallow. 



h. Side. — c. Upper view of head, magnified. 

 Figure 2. lihinostoma occipitale, Hallow. 



h. Side. — c. Up]3er view of head, magnified. 

 Figure 3. Leptophis lateralis. Hallow. 



b. Side. — c. Upper view of head, magnified. 



PLATE V. 



Coronella balteata, Hallow. 



h. Side, and c, upper view of head. 



PLATE VI. 



Figure 1 . Dipsosaurus dorsalis, Hallow. 



a. Full view. — h. Portion of under surface. — c. Top of head. — d. Anterior toe and 

 claw. — e. Posterior toe and claw.— y. Portion of side. — (The figures 1 c to 1 / 

 magnified twice.) 

 Figure 2. Sceloporus biscriatus, Hallow. 



a. Full view. — b. Side of head.— c. Upper, and d, lower .surface of head.— e. Fore 

 toe.—/". Hind toe. All magnified twice but the fir.it. 



PLATE VIT. 



Figure 1. Urosaurus graciosus. Hallow. 



a. Full view. — b. Under surface. — c. Top of head. — d. Side of head.— e. Femoral 

 pore. — (All magnified three diameters, but tlie first, which is natural si?ie.) 



