RErTILIA. 301 



snout. Body broad, flat. Scales small, ventral scales smooth. 

 Gular fold. Anal and femoral pores none. Toes serrate. Tail 

 slender. 



Sp. Phrynocephalus helioscopus Wagl., Lacerta helioscopa Pall., Gm., Gra- 

 VENHOEST Nov. Act. Acttd. Leop. Carol, xvi. p. 2, T. 64, figs. 9 — 14, 

 p. 934, in the soiitli of Siberia; — Phrynocephalus auritus Kaup, Lacerta 

 aurita Pall. Voyages dans plusieurs Provinces de Russie, Tom. v. PI. 9, 

 fig. I, DuM. et BiBR. Erpet. iv. PI. 42, fig. i, &c. 



B. With teeth united to the inkier side of Jaws. 



Phrynosoma WiEGM. Head covered with tuherculate scuta, 

 armed posteriorly with large spines. Palatine teeth none. Body 

 flat, aculeate. Gular fold. Tail short, broad at the base, suddenly 

 gracilescent. Feet short. Femoral pores. 



Sp. Phrynosoma orhiculare Wiegm., Lacerta orbicularis L. (in part, excl. 

 synon. of Seba referrible to Agama spinosa), Gravbnhorst 1. 1. Tab. 68, 

 pp. 911— 917, Wiegm. Herpet. Mexic. Tab. 8, fig. 1; in Mexico and also 

 in the United States. Here also belong Phrynosoma cornutum, Agama 

 cornuta Harlan, and two other species, all figured in Holbrook North 

 Americ. Herpet. iii. PI. 9 — 12. 



Sceloporus WiEGM., Trojndole^is Cuv., DuM. and Bibr. 

 Head scutate. Palatine teeth none. Large imbricate scales, dorsal 

 keeled, abdominal smooth. Large femoral pores. 



Sp. Sceloporus undulatus, Agama undidata Daud., Holbrook N. Americ. 

 Herpet. III. PL 8, North America, Mexico, West Indmn;— Sceloporus 

 torquatus Wiegmann, Herp. Mex. Tab. 7, fig. t ; from Mexico like various 

 other species, on which compare Wiegmann lib. cit. 



Tropidurus Neuw., WiEGM. {Proctotretus DuM. and BiBR., 

 Ecjyhymotes Cuv., DuM. and Bibr., not Fitz., Hoplurus Cuv., 

 DuM. and Bibr.). Head scutate, short, triangular, not distinct 

 from. trunk. Nostrils tubular. Palatine teeth distinct. Scales im- 

 bricate, mostly large, the upper carinate, acuminate, the subjugular 

 and abdominal smooth. Femoral pores none. 



Liolcemus Wiegm., Proctotretus DuM., Bibr. Throat not folded. 

 No crest at nape. Some prpeanal pores in males. 



Sp. Tropidurus chilensis Wiegm. &c. Comp. Wiegmann Nov. Act. Acad. 

 Leop. Carol. Tom. xvii. p. i. There is a certain conformity of habit with 

 the Seines. 



Tropidurus Fitz., Ephymotes Cuv. Throat folded transversely. 

 Anal pores none. Nape not crested. 



