V 
CURIOUS SNAKE 
ior 
observed a fact, which appears to me very curious and instruc¬ 
tive, as showing how every character, even though it may be in 
some degree independent of structure, has a tendency to vary 
by slow degrees. The extremity of the tail of this snake is 
terminated by a point, which is very slightly enlarged ; and as 
the animal glides along, it constantly vibrates the last inch ; 
and this part striking against the dry grass and brushwood, 
produces a rattling noise, which can be distinctly heard at the 
distance of six feet. As often as the animal was irritated or 
surprised, its tail was shaken ; and the vibrations were extremely 
rapid. Even as long as the body retained its irritability, a 
tendency to this habitual movement was evident. This Trigo- 
nocephalus has, therefore, in some respects the structure of a 
viper, with the habits of a rattlesnake : the noise, however, being 
produced by a simpler device. The expression of this snake’s 
face was hideous and fierce ; the pupil consisted of a vertical 
slit in a mottled and coppery iris ; the jaws were broad at the 
base, and the nose terminated in a triangular projection. I do 
not think I ever saw anything more ugly, excepting, perhaps, 
some of the vampire bats. I imagine this repulsive aspect 
originates from the features being placed in positions, with 
respect to each other, somewhat proportional to those of the 
human face ; and thus we obtain a scale of hideousness. 
Amongst the Batrachian reptiles, I found only one little 
toad (Phryniscus nigricans), which was most singular from its 
colour. If we imagine, first, that it had been steeped in the 
blackest ink, and then, when dry, allowed to crawl over a board, 
freshly painted with the brightest vermilion, so as to colour 
the soles of its feet and parts of its stomach, a good idea of its 
appearance will be gained. If it had been an unnamed species, 
surely it ought to have been called Diabolicus , for it is a fit 
toad to preach in the ear of Eve. Instead of being nocturnal 
in its habits, as other toads are, and living in damp obscure 
recesses, it crawls during the heat of the day about the dry 
sand-hillocks and arid plains, where not a single drop of water 
can be found. It must necessarily depend on the dew for its 
moisture ; and this probably is absorbed by the skin, for it is 
known that these reptiles, possess great powers of cutaneous 
absorption. At Maldonado, I found one in a situation nearly 
as dry as at Bahia Blanca, and thinking to give it a great treat, 
