CKOCODILIANS, LIZARDS, AND SNAKES. 263 



tobyals slightly expanded i)roximally, articulated at end of moderately 

 long hypoliyals. 



The vertebric display a zygosphenal articulation. Five cervicals dis- 

 play free intercentra, and four of them have no ribs. Eibs extending 

 to sacrum. The two sacral centra and diapophyses are distinct, but 

 the second diapophysis has a median longitudinal groove. Caudal 

 centra of the distal half of the tail segmented, and possessed for the 

 middle of the length of double diapophyses, between which the fissure 

 passes. Diapophyses long on basal third of tail. Neural spines low 

 everywhere; on the caudal vertebrai they stand at the posterior end, 

 and send a keel to the anterior end, where it is elevated into a low 

 anterior spine. Chevron l)ones intercentral. Four sternal ribs and 

 two from the xiphoid rod. 



Scapula very short, with a large superior proscapula. Coracoid with 

 two notches. Sternum wide and emarginate posteriorly, spreading the 

 xiphoid rods far apart. Xo fontanelle. 



Pelvis with the pubis transverse and the pectineal process external. 

 Ischia rather slender, with a short symphysis, and each with a long 

 tuberosity. 



This genus is remarkable for the combination of characters it dis- 

 plays. The zygosphenal articulation allies it to Dipsosaurus and the 

 larger Iguanid.e, but the separated ceratobranchials, and the wide 

 sternum are like that of the Phryuosomas, with the exception of the 

 fontanelles. The transverse pubes have a similar significance. 



Of the habits of the species of Sauromalns, Dr. Stejneger remarks:' 



It Las long been suspected that these lizards live on vegetable food, in fact, Dr. 

 Streets' statement {loc. cU.) as to the nature of their excreta' made it almost certain; 

 but, to remove all doubt, I had the stomach of one of the large specimens (collected 

 by Mr. Townsend) opened, and Prof. W. B. Barrows, of the U. S. Department of Agri- 

 culture, had the kindness to submit the contents to one of the experts in that line 

 for examination. He reports that the contents are exclusively vegetable and that 

 the numerous seeds are those of a malvaceous plant, probably Sphceralcea Jiastiilata. 



Two species of this genus are known, which differ as follows: 



Nuchal scales spiny, the largest almost as large as largest preauricular spines; dorsal 

 scales ending posteriorly in a long obtuse spine; dorsal scale rows average 16 to 

 a head length; number of ventral scale rows from gnlar fold to anus averages 

 118; number of scales round thickest part of tail averages 50; femoral pores, 

 12-15; larger average length, 510 mm. (Stejneger) S.hispidus. 



Nuchal scales tubercular or smooth, none of them half as large as largest preauric- 

 ular spines; dorsal scales squarish, smooth, without spine; dorsal scale rows 

 average 32 to a head length; number of ventral scale rows from gular fold to 

 anus averages 165; number of scales round thickest part of tail averages 76; 

 femoral pores, 15-18; size medium, length 314 mm. (Stejneger) S.ater. 



I Proceedings, U. S. National Museum, XIV, 1891, p. 411. 



