REPTILES OF THE PACIFIC COAST. 31 



fiat topped, covered above and laterally with smooth 

 skin. Upper jaw not hooked, sometimes notched at 

 symphysis. Skin of neck and gular region granular. 

 Limbs covered with scales; anterior with five, posterior 

 with four, digits webbed to bases of long claws. Tail 

 moderately long, tapering to tip, covered with scales in 

 irregular whorls. 



The coloration is very variable. In some specimens 

 the carapace is olive or horn-color with few or no mark- 

 ings. In others a few broken and very irregular black 

 lines are present. These lines frequently have become 

 so numerous that, blending and crossing, they appear 

 as the ground color, or form a very fine network through 

 which the original ground color shows more or less in- 

 distinctly. Sometimes the carapace is almost black. 

 The plastron is yellow, usually irregularly blotched with 

 black or brown, or with dark lines along the posterior 

 margins of the plates. The upper surface of the head 

 may be unicolor or finely or coarsely reticulated with 

 yellow and black. The chin and throat are yellow, often 

 dotted with brown or black. The limbs and tail are 

 yellow marked with black or brown, or brown marked 

 with yellow. In young, the plates of the carapace show a 

 central area of brown sometimes surrounded by a band 

 of lighter brown or dull yellow, and the markings on 

 the limbs, tail, neck, and gular region form irregular 

 longitudinal bands. 



Length of carapace 27 45 90 120 125 164 



Length of plastron 24 40 79 109 117 153 



Width of carapace 27 42 71 101 100 130 



Width of plastron 21 33 57 85 85 105 



Length of tail 21 30 36 38 48 65 



Distribution. — T!ie Pacific Terrapin probably occurs 

 in all the fresh waters of the Pacific Slope from Lower 



