13. AMBLYSlOMA. 49 



13. Amblystoma aterrimum. 



Amblystoma aterrimum, Cope, Froo. Ac. Philad. 1867, p. 201; 

 Strauch, Salam. p. 65. , 



The series of palatine teeth commence only opposite the middle 

 of the posterior mar^n of the choanse, and describe a slight curve 

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

 rioi?, then turn abruptly inwards and slightly backwards, making a 

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

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

 oval, intermediate in form between A. tenehrosum and A. tigrinvm, ; 

 canthus rostralis distinct. Limbs very stout, jast meeting when 

 laid along the side ; toes short and flattened. TaU 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 Eocky Mountains. 



14. Amblystoma tenebrosum. 



Amblystoma tenebrosum, Baird 8f Oir. Proc. Ac. Philad. 1853, 



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



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



Xiphonura tenebrosa, Qir. U.S. Expl. Exped., Herp. 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 choanse, not extending beyond their outer 



margin. Tongue large, plicse .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 wrisfc-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. Grejdsh 



l^own above, marbled with dark brown ; dirty white beneath, 



immaculate. 



Total length 150 millim. 



Prom snout to cloaca 82 



Head 20 



Width of head 18 



Fore limb 24 



Hind limb 30 



TaU 68 



Oregon; California. 



o. Hgr. 2 . Sumass Lake N. A. Boundary Commission 



{J. K. Lord). 



