422 BULLETIN 34, UNITED STATES NATIONAL MUSEUM. 



Male-. 



Inches. 



Total of iiiiul foot 4.70 L 59 



Chord of head 1.14 .^^8 



Width of head 1.10 .37 



Tympanum 47 . IG 



Eye .- 38 .13 



Total length 



Arm from elbow 



Femur 



Inches, 



2.96 



1.20 



1.40 



1.00 

 .40 

 .47 



Tibia 



1.40 



.47 



Tarsus 



76 



.26 



Foot 



1.46 



.49 



Female (Carlisle, Fa.), 

 Total 3.30 1.00 Total ofleg 5.00 1.51 



Femur 1.55 .47 



Tibia 1.55 .47 



Tympanum 32 .10 



A Carlisle, Pa., speciineu, when liviDg, was colored as follows: Above 

 aud on sides, greenish-biown, with rounded brown spots uniformly dis- 

 tributed, and about as large as the pupil of the eye; about twenty be- 

 tween the lateral folds ', head and body anteriorly bright grass-green ; 

 beneath greenish-white, unspotted, the color of the sides fading into it; 

 the buttocks mottled with brown and yellowish white; femur and leg 

 with three or four transverse dark bands; fore limbs with scattered 

 blotches not banded; iris black, mottled with golden. 



The specimens from Lake Superior are types of the E. nigricans of Pro- 

 fessor Agassiz, which I can not distinguish. They exhibit a greater 

 amount of black mottling and blotches on the inferior surface than usual, 

 but this is shared by individuals from more southern localities. Speci- 

 mens from Maine and Louisiana are still darker, the buttocks being 

 nearly uniform black. 



In carefully comparing quite a number of specimens from the South 

 and ISTortb, I find it impossible to establish definite characters by which 

 to distinguish a E. fontinalis from B. clamata. At first sight the 

 Southern individuals, which happened all to be of medium size, ap- 

 peared to be more free from the coarse pustulations ; but on the other 

 hand to have the fine asperities more numerous and closer and the head 

 rather narrower; but the same conditions were seen in some North- 

 ern specimens. The tympanum is very large in the males, though vary- 

 ing with the individuals. As in the Northern specimens, some are 

 nearly immaculate; others mottled above and below, and of various 

 shades of color, from black above to olivaceous.* 



This is especially a species of an aquatic life, not hunting on land, 

 but haunting all kinds of waters, from springs to river banks. It lives 

 singly, in pairs, or in small companies, but never in swarm,s like the 

 a. virescens. It is not noisy, contenting itself with an occasional nasal 

 "chuug,"and frequently uttering a sharp cry as it plunges into the 

 water to escape the pedestrian on the bank. It is a good leaper aud 

 swimmer. 



* Professor 13aird had an opportunity of examining the specimens from which Dr. 

 Holbrook made his description aud figure of F. clamlfans without seeing occasion 

 to change the opinion above expressed. 



