8 UNITED STATES AND MEXICAN BOUNDARY 



31. DIPSOSAURUS DORSALIS, H a 1 1 o w e 1 1 



Plate XXXII, Figs. 7—13. 



Crotaphytus dorsalis, B. & G. Pr. A. N. Sc. VI, Aug. 1852, 126 

 Dipsosaurus dorsalis, Hall, Pr. A. X. S. VII, June, 1854, 92. 



4178. Colorado desert. A. Schott. 



32. CALLISAUEUS VENTRALIS, B a i r d . 



Homalosaurus ventralis, Hallowell, Pr. A. X. Sc. VI, October, 1852, 179 



2981. Colorado desert, A. Schott. 



33. HOLBROOKIA MACULATA, Girard 



Holbrookia maculata, Girard, Pr. Am. Assoc, for 1850-1851, 201 



2807. San Antonio to El Paso. J. H. Clark. 



34. HOLBROOKIA PROPINQUA, B. & G. 



Holbrookia propinqua, B. & G., Pr. A. N. Sc. VI, Aug. 1852, 126. 

 2671. Indianola to San Antonio. J. H. Clark. 







35. HOLBROOKIA APPROXIMANS, B a i r d . 



a 



Holbrookia approximans, Baird, Pr. A. N. Sc. Dec. 1858. 



Sp. Ch. — Similar in size and general character to H. maculata. Tail shorter than body. Two small 

 vertical indigo black patches on the side of the belly, entirely visible from below, with a light blue 

 areola. Central point of belly about opposite the middle point between the two patches. No light 

 stripe on side of neck. Upper parts and sides gray, sprinkled with whitish. Head broad, very convex j 



above. Hind foot about one-third the head and body. 



Tamaulipas. Lt. Couch. 



36. HOLBROOKIA TEXANA, B. & G 



Plate XXX 



Wiegmann's Archiv 



Holbrookia 



2659. San Pedro, Texas. J. H. Clark. — 2782. Colorado desert, California. A. Schott 



37. HOLBROOKIA AFFINIS, B. & G. 



Holbrookia affinis, B. & G. Pr. A. N. Sc. VI, Aug. 1852, 125 



2667. Sonora. J. H. Clark. 



38. TAPAYA HERNANDEZII, Girard. 



Tapaya hernandezii, Girard, Herp. U. S. Ex. Ex. 1858, 395. 



Sp. Ch. — Head large, depressed; vertex broad, slightly inclined anteriorly, snout protruding. Cephalic 

 plates small; occipital and temporal spines small and conical. External ears simple, granular. Mental 

 scales very small; the series adjoining the sub-maxillar shields larger than the rest. Several folds under 





