338 TEETD^. 



two nasals. Eyelids developed. Ear exposed. Limbs well deve- 

 loped, each with five digits, the toes with a feebly denticulated 

 fringe laterally, inferiorly with small squarish scales. Dorsal lepi- 

 dosis comj)osed of small scales intermixed with very large keeled 

 tubercles ; ventral plates small, elongate subquadrangular, feebly 

 keeled, forming regular series. A double collar fold. Femoral 

 pores. Tail strongly compressed, with a double denticulated keel 

 Buperiorh'. 



Guianas and Basin of the Amazon. 



1. Dracaena guianensis. 



Ada guianensis, Gray, Cat. p. 25. 

 Dracaena guianensis, Dand. Rept. ii. p. 423, pi. xxviii. 

 Teius crocodilinus, Merr. Tent. p. 62. 

 Thorictis guianensis, Wagl. Syst. Amph. p. 153. 

 Teius (Ada) crocodilus, Oray, Griff. A. K. ix. Syn. p. 28. 

 Thorictes dracaena, Dum. ^ Bibr. v. p. 56 ; Duvern. R. A., Rept. 

 pi. X. bis. fig. 2. 



Head large, not depressed, subpyramidal. Nostrils opening on 

 the upper surface of the snout, on the canthus rostralis ; anterior 

 nasals forming a long suture. Upper head shields : a pair of naso- 

 frontals, three smaller prsefrontals on a line, followed by several 

 irregular small shields, a large frontal, a pair of frontoparietals, 

 three subequal parietals on a line, four or five supraoculars ; occiput 

 with numerous small shields ; a row of three or four large supra- 

 temporals ; two or three loreals and several small frenoorbitals ; a 

 row of infraorbitals ; labials large, eight or nine upper and eleven 

 to thirteen lower ; chiu-shields, an anterior and nine or ten pairs, 

 all except the anterior sepai'ated from the labials by smaller shields, 

 the outer row of which is the largest ; gular and mesoptychial 

 scales flat, subhexagonal. Dorsal scales small, irregular, intermixed 

 with irregularly arranged large oval strongly keeled tubercles. Ab- 

 dominal scales small, narrow, feebly keeled, in thirty-four or thirty- 

 six transverse and about forty longitudinal series. Praeanal scales 

 small, irregular. Scales on the limbs small. Four or five small 

 pores on each side in front of the prjeanal region and two or 

 tbree under each thigh. Caudal scales narrow, feebly keeled, 

 forming annuli ; the dorsal tubercles are gradually modified into a 

 strong double crest along the upper surface of the tail. Olive- 

 brown above, flanks with more or less distinct lighter spots ; the 

 sutures of the labials and chin-shields black ; lower surface yel- 

 lowish, marbled with blackish. 



centim. centim. 



Total length 83 Fore limb 11-5 



Head 8-5 Hind limb 15 



Width of head .... 5-5 Tail 50 



Body 24-5 



Guianas and Basin of the Amazon. 



