424 



BOULENGER. 



Male with internal vocal sacs; fore limbs thickened ; and large pad 

 on the inner side of the first finger. 



Nasal bones moderately large, in contact with each other and with 

 the ethmoid, which is largely uncovered in front. 



r 



Measurements in Millimeters 



1. 2. 3. 4. 5. 6. 7. 8. 

 c?crcf9999<:f 



From snout to vent 56 55 55 76 63 63 60 58 



Head 19 19 19 24 20 18 19 20 



Width of head 21 21 20 27 21 19 21 21 



Snout 6 6.5 6 7 6 6 6.5 6 



Eye 6 6.5 7 8 7 6 6.5 6 



Interorbital space 2.5 2 2 3 2 2 2 2 



Tympanum 6 8 8 6 5 5 5 8 



Fore limb 33 35 35 44 36 36 35 32 



1st finger 6.5 7 6 8 7 7 7 7 



2nd " 6.5 7 6 8 7 7 7 7 



3rd " 10 10 9 13 9 9 10 9 



4th " 6 6 5 8 6 6 6 6 



Hind limb 91 91 91 121 94 93 98 91 



Tibia 26 26 26 38 27 27 28 27 



Foot 32 34 33 40 34 34 34 33 



3rd toe 19 20 20 22 20 20 • 20 18 



4th « 28 29 27 33 29 29 30 26 



5th " 20 22 20 23 20 20 22 19 



1-7. Lucknow, Ontario. — 8. Eustice, Maine. 



Habitat. — Southern Canada and New York to Montana and Utah. 



This species is very closely allied to R. catesbiana, and I have failed 

 to find a single distinctive character that will apply to all specimens, 

 regardless of size. The two species are thus contrasted by Cope in 

 his key: — 



Dorsal fold, size of tympanum, and extent of web variable; length 

 not exceeding 6 centimeters; large dark spots on the back. 



R. septentrionalis. 



No dorso-lateral dermal fold; web generally leaving one phalange of 



fourth digit free; length reaching 20 centimeters. . .R. catesbiana. 



Considering that our largest specimen of R. septentrionalis measures 

 76 mm. and that one smallest nearly adult R. catesbiana measures 

 78 mm., whilst large dark spots are frequent in the latter species, this 



