182 JOURNAL, NATURAL HIST, SOCIETY OF SIAM Vol. 1. 
Family. VIPERID, 
39. Vipera Russellii. J/evssell’s Viper. 
Siainese 4 WN L817 Cugu maa sao). 
The origin of the words ‘‘ maaw sao,” meaning ‘ sleepy cat,” is 
obscure, but may refer to the lethargic disposition of this creature. 
As far as I am aware, the only specimen of this poisonous snake 
that has been found in Bangkok was one killed on the grounds of the 
Sports Club several years ago. It has been met with in several 
localities near Bangkok, but appears to be nowhere common. My 
collector once caught one in the roof of an attap shelter upon a raft at 
Sam Kok, an unusual position to find this snake in, as its corpulent 
build does not at all fit it for climbing. Itis no doubt in this way, 
namely drifting down the river upon some log or floating structure, 
that most of them find their way to us from the North. Russell’s 
Viper is not usually accounted a lover of the water, and the wet paddy 
plains of this part of the country, are probably not to its liking. 
In disposition it is sluggish in the extreme, and will usually 
not attempt to move out of the way when met with. The three occa- 
sions that I know of, when snipe shooters have encountered it, all 
confirm this, the snake making no attempt to escape and allowing 
itself to be shot at close quarters. 
The only specimen I ever kept alive, fed readily upon mice. 
Poison. The poison of Russell’s Viper, although less toxic than 
cobra venom, is fatal to man, death occurring in the cases which have 
been recorded, in about 24: hours or longer. 
Length. 1600 mm. 
Color (in life). Light brown above, with three longitudinal 
chains of large dark brown oval spots, the dorsal row somewhat larger 
than the two lateral ones. The spots have a black periphery and 
are edged with white. Between them are two other series of spots, 
considerably smaller and much elongated, and others adorn the flanks 
lower down. Belly white, with dark semi-lunar spots. Head with 
dark symmetrical markings, including a lozenge shaped patch upon 
the forehead, another patch below the eye, and a streak from the eye 
to the angle of the mouth. The photograph is excellent. Upon the 
superficial resemblance of this snake to the harmless Dipsadomorphus 
multimaculatus 1 have already remarked. 
