3. CENTKOPVX. 339 



a. Ad., stuffed. Para. 



b. (S. Sautarem. H.W.Bates, Esq. [C.]. 



c. 2 . Upper Amazon. 



d. HgT. Cashiboya. Messrs. Veitch [P.], 



3. CENTROPYX. 



. Kentropyx, Spix, Spec. I\ov. Lacert. Bras. p. 21. 

 Pseudoameiva, Fitzing. N. Class. JRept. p. 21. 

 Trachygaster, IJ'at/L Si/st. Amph. p. 154. 

 Centropyx, Wiegm. Herp. Mex. p. 9} Dum, ^' Bibr. v. p. 146; Gray, 



Cat. p. 23. 

 Acanthopyga, Gray, I, c. 



Tongue loDg, its scaly portion glightly widened and emarginate 

 posteriorly, retractile at the base. Lateral teeth compressed longi- 

 tudinally, tricuspid. Head with large regular shields ; anterior 

 nasal in contact with its fellow ; nostril in the suture between two 

 nasals. Eyelids developed. Ear exposed. Limbs well developed, 

 each with five digits, the borders of which are serrated. Dorsal 

 scales small or large, juxtaposed or imbricate, usually keeled ; 

 ventral plates large, imbricate, keeled, forming regular series. A 

 strong collar fold, with a row of large scales. Femoral pores. Tail 

 cyclo-tetragonal. 



South America. 



Habit lacertoid. Head shields : a frontonasal, two prsefrontals, 

 a frontal, two frontoparietals, two parietals, an interparietal, two 

 occipitals, three or four supraoculars, four or five supraciliaries ; a 

 rostral, an anterior and a posterior nasal, a loreal, three or four infra- 

 orbitals, six or seven upper labials ; a mental, five or six lower 

 labials ; an anterior chin-shield and five or six pairs, the first pair 

 forming a suture. Caudal scales large, imbricate, strongly keeled. 



Synopsis of the Species. 



I. Median dorsal scales much larger than laterals, strongly im- 

 bricate, keeled. 



Enlarged dorsal scales very large, with 



sharp keels forming fourteen straight 



longitudinal lines 1. striatus, p. 340. 



Enlarged dorsal scales smaller, the keels 



not continuous and directed towards 



the median line of the back 2. intermedins, p. 340. 



II. Median dorsal scales a little larger than laterals, hexagonal, 

 juxtaposed, keeled. 



The femoral scales which touch the row 



of femoral pores anteriorly hardly as 



large as the median gulars 3. calcarafus, p. 341. 



These scales larger than the median gulars, 4. ^'f ?f''f€^J«, p. 342. 



III. Dorsal and gular scales all smootli. 5. altawazonicus, p. 342. 



z2 



