A NEW LIZARD OF THE GENUS PHRYNOSOMA, FROM 



MEXICO. 



By Leonhard Stejneger, 



Curator, Diiisiov of Reptilex <in<1 Batrachians. 



A short time ago Mr. Raymond L. Ditmars, curator of reptiles in the 

 New York Zoological Park, sent me, from his private collection, two 

 small Phrynosomas, one of which he had kept alive for some time and 

 which had attracted his attention l)y its peculiar habits. They were 

 given to him in 1897, by a Mr. Eustace, according to whose statement 

 they were taken '■'a short distance over the border of Arizona, in old 

 Mexico, State of Sonora.'' 



The most cursory examination of the specimens showed them to 

 belong to an undescribed species of ''horned toad,'' if indeed a Phry- 

 nosoma practically without horns can be so designated. Mr. Ditmars 

 has kindly presented the specimens to the U. S. National Museum, and 

 I take great pleasure in naming this very interesting species after 

 him. 



PHRYNOSOMA DITMARSl, new species. 



Diag7iosis. — Tympanum naked; nostril in the line of canthus ros- 

 tralis; one series of marginal abdominal scales; a single series of. 

 enlarged gular scales; submandibulars larger than lower labials; no 

 horns; a prominent ridge from tip of postorbital boss to outer enlarged 

 temporals; ventrals strongly keeled; lower jaw enormously developed 

 posteriorly, with 5 to 7 rows of keeled scales between the lower labials 

 and the submandibulars. » 



Habitat. — Mex ico . 



7yp6^— Cat. No. 36022, U.S.N.M.; State of Sonora, Mexico, not far 

 from boundary of Arizona; Ditmars collection. 



Dexcriptio7i of tyjM. — Adult male. Head much broader than long; 

 nostril in the line of canthus rostralis; tympanum entirely posterior, 

 vertical to the axis of the body, concealed in the anterior neck fold, 

 naked; no horns, the scales which in the other species form moi-e or less 



Proceedings U. S. National Museum, Vol. XXIX— No. 1437. 



565 



