138 PROCEEDINGS OF THE ACADEMY OF [1885. 



A REVIEW OF THE GENUS PHRYNOSOMA. 

 BY ALAN F. GENTRY. 



Phrynosoma Wiegmann, in Oken, Lis. xxi, 1S28, p. .">fi7: Wagler, Natnrl. Syst. Amph., 

 L830, p. 145; Gruy, Cat. Liz. Brit. Mus., 1845, p. 227: Dumeril .1 Bibron, Erpet. 

 gener., iv, 18J7, p. 311; Holbrook, N. A. Berp., ii, 1842, p. 85 ; Fitzinger, Syst. 

 Kept., 184.1, p. 78; A. Dumt'iil, Cat. Moth. Rept., i, 1851, p. 78; Girard, Stans. 

 Expl. Vail. Gt. Salt Luke, 1852, p. 354; (iirard, Herp. U. S. Expl. Exped., 

 1 s 5 •< , p. 388; Dumeril <t Bocourt, Miss. Sci. au Mex. et Am. Crnt., 1870, p. 

 217; Cope, Chock List X. A. Batrach and Rept.. 1875, p. 19. 



Anota Eallovell, Proc. Acad. Nat. Sci. Phila., 1832, p. 182. 



Gen. Char. — Head short, cordiform, elevated at the vertex, and 

 armed behind and on the sides with strong spines, variable in 

 length and number. Cephalic plates small, rugose and polygonal. 

 Palatine teeth wanting. Gular fold present. Auricular aperture 

 inconspicuous in certain species, or entirely absent. Body short, 

 rounded, depressed, and ordinarily fringed. Dorsal and caudal 

 crests lacking. Limbs short, digits moderately developed. Tail 

 comparatively short. Femoral pores present, but anal wanting. 



This genus, which is probably the best defined and the most 

 strikingly distinct of its family, is wholly restricted to North 

 America. Its northernmost range, so far as has been determined, 

 is the boundary line between the United States and the British 

 possessions, Dr. Coues having met with it in the region of the 

 Milk River during the summer of 1814, while its southern limit 

 is the scope of country that occupies the terminus of Mexico. 

 Montana, Dakota, Nebraska, Kansas, Indian Territory. Texas, 

 and the countries stretching thence to the Pacific, are the only 

 portions of the Union, as far as are known, that have yielded evi- 

 dences of its existence. Of the many specie- which have been 

 described from this area, but twelve seem to me as valid, seven 

 being denizens of the United States, and the residue of the table- 

 lands Of Mexico. 



While differing from previous writers in an estimate of the 

 number of species, 1 am consl rained to disallow any separation of 

 the genus into subgenera, as has been done by GKrard, and by 

 Dumeril and Bocourt, since the characters upon which they are 

 founded are not sufficiently strong to warranl such a division. 

 The interests of science are doubtless best subserved by consider- 

 ing bul a single undivided genus, whose species-representatives, 



