THE POISONOUS SNAKES OF INDIA 



311 



SUPRAOCULARS UNDIVIDED (see So, Fig. 



26). 2ND SUPRALABIAL DISTINCT FROM LOREAL 



pit (see Fig 27) 



2ND SUPRALABIAL WITH A FURROW IN ITS 

 UPPKR PART DIRECTED INTO LOREAL PIT 



(see Fig 28). 

 MANY SMALL SDBOCOLAR SCALES 



{see Fig. 28 i 



AN ELONGATE SOBOCULAR 

 SHIELD {see So, Fig. 27). 

 SCALES _'l OR 19 IN POSTERIOR 



BODY (see Fig. 7). 

 Nasal ad 1st supralabial partially 

 or completely united (see Fig. 29). 

 Scales in midbody 29 rows {see 



Fig. 7) 



„ ,, ., 27 to 23 rows. 

 Nasal -and 1st supralabial dis- 

 tinct (see Fig. 31.) 



SCALES 17 OR 15 LV POSTERIOR BODY 

 (see Fig. 7) 



Supralabials 7 or 8 (see Fig. 32) 



9 to 12 (see Fig. 



33) ... 



SUPRAOCULARS DIVIDED (see So. Fig. 34.) 



Subocular touching 3rd supralabial {see So, 



Fig. 34)... 



Lachesis strigatus. 



monticola. 



not 



{see So, Fig. 

 35) 



cantoris. 

 purpureomaculatu$. 



mucrosquamatut. 



jerdonii. 

 gramineu*. 



trigonocephaly- 



ariamallennis. 



Ancistrodon hitnalayanus — The Common Himalayan Viper. 



Identification. — The top of the head has the shields in front enlarged, 

 and the scales in the middle of the body are arranged in 21 to 23 rows. 

 These combined characters will distinguish this from the other pit- 

 vipers, and even if the head is badly mutilated short of dissolution, I 

 think the enlarged head shields will be generally clearly recognized. 



Distribution.— It is confined to the Himalayan region, including the 

 Khasi Hills of Assam, ai. altitudes between 5,000 to 10,000 feet, and ia 

 exceedingly common in some localities (Lidda Valley Kashmir). 



Poison. — In spite of its aburdance I only know one authentic record 

 of a bite inflicted by this species. A collector of Mr. P. W. Mackin- 

 non's was wounded in tr\ing to capture one recently near Mussoorie. 



