114 UNIVERSITY OF COLORADO STUDIES 



Large numbers of these turtles are marketed every year. C. ser- 

 pentina ranges over the United States and southern Canada east of 

 the Rocky Mountains, and south into Ecuador. 



Colorado specimens. — University Museum: White Rocks, near Boulder, 

 September 17, 1910 (310 mm.), F. Rohwer and J. Rowland, No. 258; Wray, 

 October 27, 1912 (125 mm.), M. M. Ellis, No. 259; Colorado State Historical and 

 Natural History Museum: Wray, May 21, 1904 (180 mm.), H. G. Smith; reported 

 by D. M. Andrews from Boulder Valley, several times during the past ten years; 

 by F. Rohwer, a dead specimen at the same time and place the one above recorded 

 was caught; by N. deWitt Betts, Base-line Reservoir, southeast of Boulder, 191 1; 

 common at Greeley by Beardsley. 



Family Kinosternidae 



The Mud Turtles 



Rather small, strictly aquatic turtles, characterized by the much 

 elevated carapace and the narrow body, resulting in a somewhat 

 compressed appearance for the animal as a whole. A family of a few 

 species confined to the Americas. Of the two North American genera 

 one is represented in Colorado by a single species. 



Genus KINOSTERNON Spix 

 Kinosternon Spix, Species Novae Testudinum, p. 17, 1824. 



^ Kinosternon flavescens (Agassiz) 

 Yellow-Necked Mud Turtle 



Platythyra flavescens Agassiz, Contrib. Nat. Hist. U.S., Vol. I, p. 430, 1857. 



Carapace narrow and much elevated in the median line, smooth 

 or in young specimens with a very indistinct dorsal keel, very slightly 

 if at all notched on the anterior margin, general outline elliptical; 

 costals, 4 on each side; neurals, 5; marginals, 23; plastron large, 

 covering most of the ventral surface, lobes movable so that they may 

 be drawn against the margin of the carapace and enclose the head and 

 feet; plastral plates, 11 or 9; feet rather broadly webbed; digits, 5-5, 

 claws, 5-4; size small, length of the carapace up to six inches. 



General color yellowish brown or greenish brown above; plates 



