Il6 UNIVERSITY OF COLORADO STUDIES 



terior region somewhat extended into a shelf beyond the general 

 curvature of the carapace; plastron wide, of 12 plates; feet well 

 webbed; digits, 5-5; claws, 5-5; size medium, large specimens about 

 twelve inches in length. 



Dorsal color olive green or brown, usually with a reddish or bronze 

 cast; plates often distinctly margined with black; plastron yellowish, 

 with two dark brown or black longitudinal blotches, extending across 

 each plate excepting the first two, separated by a narrower area of the 

 ground color (although they may be confluent) , and irregularly joined 

 to those of the next plate, forming two more or less well-defined 

 concentric ellipses; other parts of the plastron often blurred with 

 blackish; marginal region below, greenish, crossed by numerous 

 small fight streaks, some of which may be red but most of which 

 are orange or yellow; under parts of the head with numerous longi- 

 tudinal stripes; feet greenish above, with a bright yellow mid- 

 dorsal stripe, breaking up and sending a branch down each digit, 

 below yellowish. 



This turtle ranges from the Mississippi River west to the Rocky 

 Mountains and north into British Columbia. It has also been taken 

 in Illinois and northern Michigan. 



Colorado specimens. — University Museum: Boulder, June 24, 191 1 

 (160 mm.), No. 125; Wray, October 27, 1912 (120 mm.), M. M. Ellis, No. 260; 

 Castle Rock, June 9, 191 2 (175 mm.), M.M.Ellis, No. 261; Ft. Morgan (165 mm.), 

 H. W. Clatworthy, No. 263; east of Boulder (125 mm.) ; Colorado State Historical 

 and Natural History Museum: Denver, July 31, 1900 (165 mm.), H. G. Smith; 

 Denver, August 25, 1900 (150 mm.), H. G. Smith; State Teachers' College Museum: 

 Cache la Poudre, Platte River at Greeley and Lakes near Greeley, A. E. Beardsley ; 

 reported by J. Henderson, Platteville, June, 191 2; as abundant in some of the 

 lakes east of Boulder. 



Genus TERRAPENE Merrem 



Terrapene Merrem, Versuch Syst. Amphibien, p. 27, 1820. 



The Colorado species of this genus are two. 



a. Four digits on the hind foot T. ornata (Agassiz) . 



aa. Three digits on the hind foot T. triunguis (Agassiz) . 



