54 EEPOKT ON A COLLECTION FROM !. ; 



large supraoculars, preceded by a small fourth and two or three granules ; nostril piei'ced 

 in a single nasal, which, like the loreals and suboculars, is in contact with the upper 

 labials ; latter, seven in number, fourth largest ; four lower labials ; chin-shields, one 

 anterior and two pairs. Gular scales smooth, smallest on a zone connecting the ears ; 

 collar bordered by six plates. Nape and back covered with small keeled scales inter- 

 mixed with large, oval, sharply keeled tubercles, disposed very irregularly, but avoiding 

 the vertebral line ; smaller tubercles on the sides. Ventral plates rounded posteriorly, 

 imbricate, in 8 or 10 longitudinal and 28 transverse series ; the plates of the four 

 median rows subequal, about as long as broad. Three slightly enlarged praeanal plates, 

 forming a triangle. 18-20 femoral pores. Tail feebly compressed, Avith the pair of 

 dorsal keels, formed by enlarged tubercles, feel)ly developed. Uniform blackish brown 

 above, whitish beneath. 



Totallength 183 millim. From end of snout to vent ... 59 millini. 



Head 14 „ Fore limb 19 „ 



Widthofhead 8-5 „ Hind limb 27 „ 



From end of snout to fore limb... 2.3 „ Tail 124 ,, 



A single specimen ( 6 ) from the foot of Mt. Roraima, 3500 feet. 



5. PmoNODACTYLUS LEUCosTiCTUS, sp. n. (Plate 5. figs. 2-2 c.) 



Snout short, obtusely pointed; eai'-opening a little smaller than the eye-opening. 

 Frontonasal single, a little broader than long ; prsefrontals well developed, forming a 

 median suture ; interparietal large, hexagonal, larger than the parietals ; two pairs of 

 occipitals ; four supraoculars ; nostril pierced in a single nasal ; no loreal ; six upper 

 and five lower labials ; chin-shields very large, one anterior and four pairs, the first two 

 forming a suture, the two others separated on the median line by granules ; two 

 longitudinal rows of large transverse gular shields ; five collar-shields. Dorsal scales 

 hexagonal, strongly keeled ; lateral scales small, roundish, smooth ; 26 scales, including 

 the ventrals, round the middle of the body; 29 scales from occiput to base of tail. 

 Ventrals large, in 8 longitudinal and 19 transverse series. Four large praeanal shields, 

 forming a cross. 6 femoral pores on each side ( S ). Tail above with hexagonal 

 keeled scales, beneath with tetragonal smooth scales. Black above and beneath; each 

 scale or shield with one to three white dots, these dots larger on the ventral shields ; 

 chin white. 



Totallength 127 millim. From end of snout to veut ... 50 millim. 



Head 10 „ Fore limb 13 „ 



Widthofhead 6 „ Hind limb 19 „ 



From end of snout to fore limb... 19 „ Tail 77 „ 



A single specimen ( $ ) from the summit of Mt. Roraima, 8600 feet, 

 o. Lachesis lanckolatus, Lacep. 



