58 UNIVERSITY OF COLORADO STUDIES 



posterior margin of the eye and running parallel to the mid-dorsal 

 stripe; ventral parts whitish, yellowish or greenish. 



This species is almost always found on the ground, where it hides 

 away under loose stones or fallen timber. Its generic name signifies 

 "chorus-loving," and refers to the habit of the species of singing more 

 or less in concert in the early spring. The loud voice of the male is 

 the result of the reinforcing resonance given by the expanded gular sac. 



Range, United States generally, abundant in the West and Rocky 

 Mountain region. This species is recognized by some authors as but 

 a variety of C. nigritus (LeConte). 



Colorado specimens. — University Museum: Stapp's Lake, Boulder County, 

 August 19, 1905 (18 mm.), G. S. Dodds, No. 192; Copeland Park, Boulder County, 

 September 6, 1907 (2 specimens, 18 and 22 mm.), S. A. Rohwer, No. 193; Blue- 

 bird Mine, Boulder County, August 5, 1908 (32 mm.), T. A. McHarg, No. 194; 

 Kremmling, August 5, 191 1 (7 specimens, 18-20 mm.), J. Henderson, No. 131; 

 Boulder, April 26, 1913, (2 specimens, 25-30 mm.), Robert Plimpton; Colorado State 

 Historical and Natural History Museum: Denver, August 7, 1889 (2 specimens, 25 

 and 40 mm.), H. G. Smith; State Teachers' College Museum: Greeley and Grand 

 Mesa, A. E. Beardsley. 



Genus ACRIS Dumeril et Bibron 

 Acris Dumeril et Bibron, Erpetologie Generale, Vol. VIII, p. 506, 1841. 



Acris gryllus (LeConte) 

 Cricket Frog 



Rana gryllus LeConte, Ann. Lyceum New York, Vol. I, p. 282, 1825. 



Head depressed and pointed, its length about 3 in the head and 

 body; length of the hind leg to the heel reaching forward to the snout 

 or beyond; male with a gular sac; size small, length under i . 5 inches. 



Color variable and changeable; generally brownish, greenish or 

 reddish, and somewhat clouded with dusky; a triangular dark blotch 

 on the top of the head between the eyes; a dark line on each side 

 from the posterior margin of the eyes. 



This frog, although a true tree frog, lives on the ground. In the 

 spring it is very noisy, its voice being very powerful because of the 

 gular sac. 



