140 PROCEEDINGS OF THE ACADEMY OP [1885. 



B. One row of pyramidal scales al the periphery of the abdo- 



men : auditory aperture conspicuous. 



a. Abdominal scales carinated ; tail very short, not 

 equal in length to the femur. 



1. One temporal on each side strongly developed and coni- 



cal, very much more prolonged posteriorly than the 

 occipitals, which are small. taunts. 8. 



2. Temporal spines moderate, flattened, four or five on each 



side, scarcely projecting beyond the occipitals, poste- 

 riorly. Braconnieri. 9. 

 6. Abdominal scales smooth ; tail of ordinary length ; 

 occipital spines projecting beyond the longest of 

 the temporals, posteriorly. platyrhinos. It). 



C. No pyramidal scales at the periphery of the abdomen ; 



auditory aperture sometimes absent on one or both sides 

 in modest um ; alwa3'S absent in Mac c alii ; abdominal 

 scales smooth. 



1. Occipital spines short, projecting about as far as the 



longest temporal, posteriorly; one row of enlarged 

 gular scales next to the inframaxillary plates. 



modes/ ma. 11. 



2. Occipital spines very long and recurved, projecting much 



farther than the longest temporal, posteriorly; one 

 row of enlarged gular scales on each side, distant from 

 the inframaxillary plate. Maccalli. 12. 



1. Phrynosoma Douglassi. 



Agatna, Douglassi Bell, Trans. Linn. Soc. Lond., xvi, L828 3 \>. 105, pi. 

 x; Harlan, Med. and Phys. Researches, L835, p. 141. 



Phrgnoxoma Douglassi Wagler, Naturl. Syst. Amph., ls:',0, p. 146; 

 Gray, Griff, Anim. King., i\, L831, p. II: Wiegmann, fferp. Mex., 

 1834, \k 5 I ; Dumeril & Bibron, Erpet. gener., iv. 1837, p. 323; 

 Holbrook, N. Am. Herp., ii. 1842, \>. 101, pi. \i\ ; Dekay, Zool. New 

 Fork, iii. 1842, p. 31 ; Fitzinger, Syst. Rept., i. 1843, p. 78; Gray, 

 Cat. Liz, Brit. Mus., L845, p. 227 ; A.ug. Dumeril, Cat. Meth. Coll. 

 Rept. Mus. Paris, 1851, \>. 78; Girard, Stans. Expl, Vail. Gt. Salt 

 Lake. L852, p. 362, pi. \ii, figs. 6 9; A.ug. Dumeril, Arch. Mus. 

 Hist. Nat. \iii. I^.")ti. p. 554 ; < lope, Proc. Acad. Nat. Sci. 1'liila., 

 1866, p. 302; Mien, Proc. Bost. Soc. Nat. Hist., xvii, 1874, p. 69 ; 

 t lope, Am. Nat.. \ii. 1879, p. 135. 



Phrynosoma orbiculare Hallowell, Sitgreaves' Expl. Zuni and Col. Riv., 

 L853, p. 125, pi. viii and ix. 



