ZOOLOGICAL SOCIETY BULLETIN 
29 
COLLARED LIZARD 
DESERT TORTOISE 
I( has a curious habit of running on the liiiul leg's 
Their burrows are excavated in the hard-packed sand 
perfect demonstration of the process of evolution 
in creating a desert type. The line is pallid, 
either pinkish, yellowish or pale gray in match¬ 
ing the sand areas over which the species is 
distributed. This reptile wanders over sand 
that is often as fine as powdered chalk and as 
the snake is comparatively heavy-bodied, it 
would be at great disadvantage in pursuing its 
prey or escaping from enemies if compelled to 
crawl like the ordinary rattler, which seldom 
leaves firmer ground or a near retreat into rocks 
or heavy clumps of vegetation. The sidewinder 
is so developed that it flattens the body and by 
loops thrown rapidly forward in a plane paral¬ 
lel to the ground, literally walks off sideways 
at an oblique angle to the direction to which the 
head is pointing. The action is quite astonish¬ 
ing to the observer not familiar with the ways 
of this snake—being utterly foreign to any 
anticipated movement attributed to serpents gen¬ 
erally. Rushing off in this fashion to a safe 
distance the sidewinder further flattens the body 
until the sides assume the sharpness of a wedge, 
then by wavy movements it shovels the sand 
over its back and sinks out of sight. In fifteen 
seconds’ time the snake is imbedded, all but tbe 
top of its head, with the short projecting horns, 
appearing like debris from a cactus. The pale 
eyes remain uncovered, but match the hue of the 
sand. 
The red rattlesnake (Crotalus exul) and the 
common rattler of the entire Pacific region 
(Crotalus oregonus ) are found in the desert 
canyons. The former wanders towards the open, 
but not far from clumps of greasewood or sage. 
The latter prefers the rocks. We found them in 
the canyons, sleek and fat, four to five feet long 
and some with a body two inches in diameter. 
In all this heat, among the sterile sand and 
rocks, no water in sight nor known to exist in 
CHUCK AW ALLA 
These creatures live among rocks on sterile mountains in the desert and amid intense heat 
