3. CENTROPYX. 339 
a. Ad., stuffed. Para. 
b. S. Santarem. H.W. Bates, Esq. [C.}. 
 D. Upper Amazon. 
d, Her. Cashiboya. Messrs, Veitch [P.]. 
3. CENTROPYX. 8 
Kentropyx, Spiz, Spec. Nov. Lacert. Bras. p. 21. 
Pseudoameiva, Fitzing. N. Class. Rept. p. 21. 
Trachygaster, Wagl. Syst. Amph. p. 164, 
Centropyx, Wiegm. Herp. Mex. p. 9; Dum. § Bibr. v. p. 146; Gray, 
Cat. p. 23. 
Acanthopyga, Gray, J. ¢. 
Tongue long, its scaly portion slightly 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 largescales. Femoral pores. Tail 
cyclo-tetragonal. 
South America. 
Habit lacertoid. Head shields: a frontonasal, two preefrontals, 
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 .........0eeeeeeee 1. striatus, p. 340. 
Enlarged dorsal scales smaller, the keels 
not continuous and directed towards 
the median line of the back ........ 2. intermedius, 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. calcaratus, p. 341. 
These scales larger than the median gulars. 4. petviceps, p. 342. 
III. Dorsal and gular scales all smooth. 5. altamazonicus, p. 342. 
22 
