204 APPENDIX F. REPTILES. 



LIZARDS. 



Six species of saurians, or lizards, belonging to six different genera, 

 were collected during the exploration of Red river. One of them has 

 proved to be new to science ; two were recently described for the first 

 time, whilst the three others have been long known to herpetologists. 



I. PHRYNOSOMA, Wiegm. 



This genus, including the so- called horned toads or horned frogs, more 

 properly horned lizards, is recognisable by a depressed, broad, and 

 subelliptical body, covered above with irregular scales, the majority very 

 small, others quite large, pyramidal, raised above the surface of the 

 skin, and scattered ail over the back, sides, and tail. The head is sub 

 triangular and provided with powerful spines or horns, giving to it rather 

 a formidable appearance, although all the species of this genus are per- 

 fectly inoffensive. There are external auditive apertures as in most 

 of the lizard tribe. 



In a monograph of the genus appended to Stansbury's Exploration 

 of the Valley of the Great Salt Lake of Utah, six species are described 

 as indigenous to North America ; another has since been added to the 

 list'. The single species collected is the most abundant of the genus. 



1. Phrynosoma cornutum, Gray. 



Spec. char. — Nostrils situated within the internal margin of the 

 superciliary ridge ; occipital and temporal spines longer and more acute 

 than in Ph. orbiculare ; a double row of pyramidal scales on the sides 

 of the abdomen ; scales on the inferior surface of the head small and 

 slightly keeled, of a general uniformity, except one row on each side, 

 somewhat larger, pyramidal, acute, slightly raised, and directed outwards 

 and backwards ; a series of very large inframaxillary plates, sharp on 

 their outer edge, the posterior one of which is transformed into a spine. 

 The plates lining the margin of the jaws are not prominent. The scales 

 of the belly are proportionally small, subquadrangular, keeled, and pos- 

 teriorly very acute ; femoral pores undeveloped, or rudimentary in the 

 female. 



