122 Lacerfiihv. 



Body moderately or rather feebly depressed. Head feebly de- 

 pressed, Ih to 1| times as long as broad, flat above, its depth ecjual 

 to the distance ])etween the centre of the eye and the tympanum, 

 its length 3} to 4 times in length to vent (3^ to 8 J times in the 

 young) ; snout pointed, as long as or slightly longer than postocular 

 part of head, with sharp canthus and nearly vertical loreal region. 

 Pileus 2 to 2^ times as long as l)road. Hind limb reaching the ear 

 or between the collar and the ear in males, the collar or a little 

 beyond in females ; foot a little longer than head. Tail nearly 2 to 

 2^ times as long as head and body. 



Nostril between four shields ; nasals forming a rather long or very 

 short suture behind the rostral*; upper head-shields with strong 

 keels and short stria? ; internasal as long as broad or a little longer ; 

 prefrontals sometimes forming a median suture, more often separated 

 by a small azygos shield or by the frontonasal being in contact with 

 the frontal ; frontal bi- or tricarinate, as long as or a little shorter 

 than its distance from the end of the snout. If to 2 times as long- 

 as l)road, of nearly equal width throughout or a little narrower 

 liehind than in front; parietals Ij to 1^ times as long as broad, outer 

 l)order sometimes feebly emarginate for the accommodation of the 

 first anterior temporal ; interparietal narrow, 2 to 2^- times as long 

 as broad (broader in the y(3ung) ; occipital small, not more than half 

 as long as the interparietal ; 3 or 4 supraoculars, first very small 

 and keeled if present,! second often a little longer than third, fourth 

 broken up into 3 to 5 keeled scales ; 5 or 6 superciliaries, first long 

 and narrow and sharply keeled, the others very narrow and separated 

 from the supraoculars by 5 or 6 keeled scales. 



Rostral not entering the nostril ; two superposed postnasals ; 

 anterior loreal as long as or shorter than second ; 4 to 6 upper 

 labials;!: anterior to the subocular, which is not or but little narrower 

 beneath than above ; two, rarely three, large, keeled upper temporals, 

 first longest ; temporal scales rhombic or hexagonal, strongly keeled, 

 larger beneath than above ; a narrow tympanic shield usually present. 



Parietal foramen usually absent. Pterygoid teeth absent. 



Four pairs of chin-shields, the two or three anterior meeting on 

 the middle line. Anterior gular scales small and granular, generally 

 enlarged, imbricate, pointed and keeled towards the collar, which 

 contains 12 to 14 pointed, strongly keeled plates; 24 to 34 scales 



* A small azygos shield between the nasals in a male from Butanga. 



t Absent in a male and in a female from the Benito Eiver. 



+ Out of 32 cases, 5 twenty-two times, 4 seven times, 6 three times. 



