Cope.] 524 [Oct. 1 



It is the first and only species of Amblystoma yet found in Alaska. 

 No. No. of specimens. Locality. Year. Collector. 



14,493. 1. Port Simpson, Alaska. 1885. T.H.Streets, U.S.N. 



Amblystoma lepttjrum Cope, s.p nov. 



This species resembles the A. cingulatum, but differs from it in the en- 

 tirely different form and proportions of the tail. Tbis part is very slender 

 in the A. lepturum, with round or vertical oval section, -without keel 

 above, and lacking very little of being as long as the head and body to- 

 gether. The legs are of the same proportions as in the A. cingulatum ; 

 that is, -when appressed they are separated by a space equal to the length 

 of the posterior foot, showing their greatly superior length to those of the 

 A. microstomum. The body is cylindric. The head is an oval, with pro- 

 duced and rounded muzzle, which projects beyond the lower jaw. The 

 animal resembles a Plethodon rather than the species of Amblystoma, but 

 its vomerine teeth and tongue have all the characters of the Amblystoma 

 microstomum. 



The vomerine teeth form a convex series extending forwards to a point 

 between the choanae, where they are slightly interrupted on the middle 

 line. The tongue is large, filling the floor of the mouth, and is exten- 

 sively free at the sides only. The external nostrils are nearly terminal 

 and are rather near together, the space between them being equal to just 

 half that between the bases of the eyelids, and about three-fifths that be- 

 tween the choanse. The width between the eyes behind is equal to the 

 axial length from the same to the end of the muzzle. The width of the 

 head enters the length to the groin seven times. The length from the 

 muzzle to the axilla enters the distance from the latter to the groin one 

 and three-fifth times. 



The lateral digits are distinct, and ihe median ones moderately elongate. 

 Their lengths, beginning with the shortest, are, fore foot, 2-5-8-4 ; hind 

 foot, 1-5-2-3-4. The phalanges are, fore foot, 2-2-3-2 ; hind foot, 2-2-3-4-2. 

 No palmar or plantar tubercles. 



The skin is perfectly smooth, and between the axilla and the groin it is 



marked by fourteen grooves. There are no dermal margins to the fingers 



or the tail. The cloacal orifice is a simple slit. There is a distinct post- 



gular fold. 



Measurements (No. 14,583). M. 



Total length 115 



Length from end of muzzle to base of tail 092 



" " " " " " groin 0515 



" " " " axilla 020 



" " " " " " canthusoris 0065 



" of fore leg 013 



" " foot 0055 



" " hind leg 010 



•< " " foot 0075 



Depth of tail at middle 0025 



