EXPLANATION OF THE PLATES, 



PLATE I, 



Emys nigra, Hallow. Half natural size. 



Crolalus ornatus, Hallow. 



a. Side view of head. 



Crotalus Iccotttii, Hallow. 

 a. Head from above. 



PLATE II. 



PLATE III, 



PLATE IV. 



Figure 1. Crotalus cerastes, Hallow. 



6. Side. c. Upper view of head, magnified. 

 Figure 2. Rliinostoma ocdpitale, Hallow. 



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

 Figure 3. LeptopJiis later alls, Hallow. 



6. Side. c. Upper view of head, magnified. 



PLATE V. 



Coronella balteata, Hallow. 



1). Side, and c, upper view of head. 



PLATE VI. 



Figure 1. Dipsosaurus dorsalis, Hallow. 



a. Full view. b. Portion of under surface. c. Top of head. df* Anterior toe and 

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

 magnified twice.) 

 Figure 2. Sceloporus biseriatus, 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 first. 



PLATE VII. 



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 the first, which is natural size.) 



