13. amblystoma. 



49 



13. Amblystoma aterrimum. 



Ainblystorna aterrimum, Cope, Proc. Ac. Philad. 1867, p. 201 ; 

 Strauch, Salam. p. Go. 



The series of palatine teeth commence only opposite the middle 

 of the posterior margin of the choanae, and describe a slight curve 

 round their inner margins to a point just in advance of their ante- 

 rior, then turn abruptly inwards and slightly backwards, making a 

 right angle with their previous course ; they converge, but do not 

 unite. Tongue large, plicae radiating from behind. Head a broad 

 oval, intermediate in form between A. tenebrosiirn and A. tigrinum; 

 can thus rostralis distinct. Limbs very stout, just meeting when 

 laid along the side ; toes short and flattened. Tail short and stout, 

 much compressed, shorter than head and body. Gular fold well 

 marked ; twelve indistinct costal grooves. Black above, lead- 

 coloured below. Total length 165 millim. 



Northern Rocky Mountains. 



14. Amblystoma tenebrosum. 



Amblystoma tenebrosum, Baird fy Gir. Proc. Ac. Philad. 1852, 

 p. 174, and U.S. JSxpl. Surv. xii. part ii. pi. 31. f. 1 ; Cope, Proc. 

 ^ Ac. Philad. 1867, p. 202 ; Strauch, Salam. p. 65. 



Xiphonura tenebiosa, Gir. U.S. Expl. Exped., Her p. p. 14, pi. 1. 

 f. 9-17. 



Palatine teeth in two nearly straight series, each slightly convex 

 anteriorly, separated by a distinct interval ; these series situated 

 just behind the line of the choaiue, not extending beyond their outer 

 margin. Tongue large, plicae radiating from behind. Head very 

 large, depressed, a little longer than broad; greatest width at 

 angles of jaws ; snout long and broad, rounded, without canthus 

 rostralis ; eyes large. Body somewhat depressed, three times the 

 distance from tip of snout to gular fold. Limbs strong; when 

 adpressed against the body the longest toe marks the wrist-joint; 

 fingers and toes short, much depressed ; carpal and tarsal tubercles 

 indistinct. Tail shorter than head and body, strongly compressed, 

 sharp-edged, except at the base, ending in a point. Skin smooth ; 

 no parotoids ; a strong gular fold ; twelve costal grooves. Greyish 

 brown above, marbled with dark brown ; dirty white beneath, 

 immaculate. 



Total length 150 milli m. 



* From snout to cloaca 82 



Head 20 



Width of head 18 



Fore limb 24 



Hind limb 30 



Tail 68 



Oregon ; California. 



a. Hgr. 2 



Sumass Lake 

 (J. K. Lord). 



N. A. Boundary Commission 



