PACIFIC MUD TURTLE. Clemmys marmorata (Baird and Girard)

Field characters.—Body protected by a firm "shell," arched above flat on under surface; this shell consists of an outer horny integument, divided into numerous plates, and a supporting structure beneath composed of bone. Total length of shell up to 5-1/2 inches. Upper surface olive brown; under surface yellow, irregularly marked with black or brown.

Occurrence.—Resident in Lower and Upper Sonoran zones on west side of Sierra Nevada. Recorded at Lagrange, Pleasant Valley, and Smith Creek, 6 miles east of Coulterville. Lives in ponds and in the quieter and deeper portions of streams.

The Pacific Mud Turtle, the only species of native fresh-water turtle to be found in central California, is resident in suitable places in the lower western portion of the Yosemite section. This turtle lives in ponds and in the parts of creeks and rivers which are deep and in which the current is very slow. The site selected for a resting place is usually some rock or log projecting above the surface of the water and at the same time some distance from the shore where there is no danger of surprise by enemies which prowl along the bank. In addition to these precautions against attack, turtles are gifted with rather keen sight, and they can detect an object moving along the shore when it is still some distance away. If a person comes rapidly up to the side of a pool where some turtles are out on their resting places the animals drop at once into the water and seek safety on the bottom; usually they do not return to the surface for some time. In the fall, the turtles disappear and do not come to notice again until the return of warm weather the following spring.