Reptiles and Amphibians of Illinois. 349 



small, minute between the first aud second toes and only reach- 

 ing; the base of the antepenultimate phalanx of the fourth toe. 

 Discs at tips of digits only moderately large. 



Color above some shade of gray or brown, with narrow 

 lines of dark brown or black, the principal of which are dis- 

 posed on the back in the form of a large letter X ; pale beneath. 

 The ground color is usually pale brown. The anterior arms of 

 the X-shaped mark converge from just behind the eyes to the 

 middle of the back, where they meet; and from this point the 

 two posterior arms diverge posteriorly and ventrally. Another 

 mark behind this sometimes resembles an inverted letter V. A 

 dark band, well defined above but fading into the ground color 

 below, extends along the side of the snout to the anterior border 

 of the eye. A wider band, which includes the tympanum, extends 

 from the posterior border of the eye toward the base of the 

 anterior leg. Two lines, one above each eye, sometimes unite 

 across the median line and form a triangular spot. Iris golden, 

 pupil black. The legs above are like the back in color and are 

 banded with brown, two or three wide bands occurring on the 

 femora and on the tibiae. A dark line is generally present on 

 the posterior surface of all the legs. A dark spot overlies the 

 vent. Body and legs uniformly pale beneath, or with the throat 

 yellowish, speckled with dusky. 



Length of body, .87; from tip of snout to axilla, .44; femur, 

 .44; tibia, .5; tarsus and fourth toe, .69. These measurements 

 are from a single specimen. 



The species is sparingly distributed throughout the State. 

 Cook county (Kennicott), Aux Plains River (Ridgway), Run- 

 ning Lake in Union county. 



Though so delicate in appearance this tree-frog is really 

 one of the most hardy of our frogs. In Massachusetts 

 Mr. J. A. Allen found it the first to become active in the 

 spring, and often when the weather was severely cold. The 

 eggs were found by Prof. F. A. Putnam on the 17th of 

 April, placed singly upon plants at some distance apart. The 

 note is a clicking or piping noise. 



