CROCODILIANS, LIZARDS, AND SNAKES. 



277 



Agassiz, the distiuguisliod. director of the Museiun of Conii)arative 

 Zoology, of Ciiiiibridge, Massachusetts. 



The species of Uma may be distinguished by the following- charac- 

 ters, among others : 



Fig. 2G. 



Ptenopus gareulus S.aiith. 



1, posterior foot from below; 2, a digit from below, enlarged. 



I. Bliick crescents on the throat and a hlaclc spot on each side of the belly. 



Labial scales strongly keeled; 6 keeled suborbital scales; 8 loreal rows; hind 

 foot shorter, one-third head and body; femoral iiores 40-50; dorsal spots 

 '^1'''''^ p, scoparia Cope. 



II. Black spot on side of belly, but no crescents on throat. 



Labial scales strongly keeled; 3 or 4 keeled suborbitals; 5 or (i loreal rows; 10 

 or 11 supraocular rows; hind foot shorter, one-third head and body ; femoral 

 pores 24-28 ; dorsal spots rufous T. rtifopiinciata Cope. 



Labial scales weakly keeled; 9 loreal rows; 14 supraorbital rows; hind foot 

 longer, two-fifths head and body; femoral pores 19 U. noiata Baird. 



III. No black spots on belly or crescents on throat. 



Labial scales strongly keeled; 5 or 6 loreal rows; 10 or 11 supraocular rows; 

 hind foot shorter, one-third head and body; femoral pores 19. 



J', inornaia Cojie. 



In the young the disciform areas are imperfectly outlined. 

 All the species are from the Sonorau region. 



UMA NOTATA Baird. 



Uma noiata Baird, Proc. Acad. Nat. Sci. Phila., 1858, p. 257.— Cope, Proc. Acad. 

 Nat. Sci. Phila., 186G, p. 360.— Boulengek, Cat. Liz. Brit. Mua., 2d ed II 

 p. 207, 1885. 



Occipital plate small; nearly circular; surrounded by small plates; 

 smaller posteriorly. The supraorbital region bordered internally on 

 the median line of the head by a series of small frontal plates, those of 

 opposite sides in contact along- the vertex, which are separated from 

 the larger occipital behind by two rows of plates. Plates on the snout 

 nearly equal, those between nostrils and orbit as large on the sides as 

 in the middle, eight or nine bet\\eeu the canthal rows: can thai low 

 including one long po.sterior and one short anterior scale. Plates o'j 

 supraorbital region very small, and showing about fourteen series trans- 



