228 



VIPERID.E 



always in contact with the former, unless broken up 

 into small shields. Two to six, usually three or four, 

 small shields on the snout between the canthals, of 

 which there are two on each side, the second broadly 

 in contact with the supraocular. Supraocular well 

 developed, extending posteriorly beyond the vertical 

 of the eye, separated from the frontal by one to four 

 shields. Nine to eleven, usually ten, scales round 

 the eye, the upper preocular usually in contact with 



the nasal; either 

 a single series of 

 scales between 

 the eye and the 

 labials, or two 

 series except 

 under the centre 

 of the eye, which 

 is separated 



Fig. 34 (From Proceedings of the Zoological from the fourth 

 Society, 1893) . , . _ 



labial by a 

 single scale. Nasal single. Temporal scales all 

 smooth, or the upper faintly keeled. Upper labials 

 eight or nine, fourth or fourth and fifth below 

 the eye. Four (rarely five) lower labials in contact 

 with the chin-shields, of which there is but one 

 pair. 



Scales in twenty-one (very rarely nineteen) rows, with 

 two apical pits, strongly keeled, outer row smooth or 

 feebly keeled. Ventral shields 130 to 148 in males, 



