subfamily BOIGIN/. 
51. CALIFORNIA TANTILLA. Tantilla eiseni. 
These little snakes are rare. I found one at Witch Creek. 
They have grooved fangs and a small poison gland. The poison 
is used for subduing their prey. 
Family CROTALIDE. Rattlesnakes. 
52. PACIFIC RATTLESNAKE. Crotalus oreganus. 
Found throughout the county except in the Desert. Most 
common on the mesas. 
53. RED RATTLESNAKE. Crotalus exsul. 
Found throughout the mountains and occasionally on the 
mesas. 
54. PALLID RATTLESNAKE Crotalus mitchelli. 
Found on the eastern slope of the mountains and in the Colo- 
rado Desert. 
55. SIDEWINDER. HORNED RATTLESNAKE. Crotalus 
cerastes. 
Common locally in the Colorado Desert and in the valleys on 
the eastern slope of the mountains. Has a peculiar sidewise 
method of locomotion. 
Rattlesnakes molt the old skin two or three times each year. 
A new rattle is added at each molt; the terminal rattles wear 
loose and drop off; if the snake lives on rocky ground the rattles 
wear off faster than when the snake lives on softer ground. The 
number of rattles remaining are no guide to the age of the snake. 
Order TESTUDINATA. 
Family DERMOCHELID. Sea Turtles. 
Outer surface covered with a thick leather-like skin, limbs flat, 
paddle-like, adapted for swimming. Inhabits tropical seas, but 
occasionally straggles to temperate waters. 
96. PACIFIC LEATHERBACK TURTLE. Dermochelys 
schlegeli. 
One caught off Point Loma about 1888 was exhibited in the 
Coronado Museum. Said to have weighed 800 pounds. 
Family CHELONID. Sea Turtles. 
Outer surface covered with horny plates. Limbs paddle-like. 
Inhabit tropical seas, straggling to temperate waters. 
57. PACIFIC GREEN TURTLE. Chelonia japonica. 
Straggle to the California coast occasionally. Several have 
been seen in San Diego Bay and in Mission Bay. One was 
caught at National City several years ago. The food is said to 
be sea weeds. 
