19. DESMOGNATHUS. — 20. THOK1T7S. 79 



3. Desmognathus niger. 



Desmognathus niger, Gray, Cat. p. 40. 

 Salarnandra nigra, Green, Journ. Ac. Philad. i. p. 352. 

 Triton niger, Holbr. N. Amer. Herp. v. p. 81, pi. 27. 

 Desmognathus niger, Baird, Journ. Ac. Philad. (2) i. p. 286 ; Cope, 



Proc. Ac. Philad. 1869, p. 117 ; Strauch, Salam. p. 73. 

 Ambystoma nigrum, Dum. fy Bibr. p. 105. 

 Plethodon niger, Hallow. Journ. Ac. Philad. (2) iii. p. 344. 



Differs from the preceding in the following characters : — Series of 

 palatine teeth generally better distinguished, separate ; parasphenoid 

 patches approaching very near the palatine teeth in most instances, 

 generally confluent anteriorly. Tongue nearly round. Body stouter. 

 Tail more compressed and extensively finned. Twelve costal grooves. 

 Colour uniform black. Size larger (nearly 180 millim. from tip of 

 snout to end of tail). 



Alleghany Mountains, from Pennsylvania southward. 



20. THORIUS. 



Thorius, Cope, Amer. Nat. 1869, p. 222, and Proc. Ac. Philad. 1869, 

 p. 111. 



Tongue supported by its central pedicel, free all round, boletoid. 

 Palatine teeth in a short transverse series; parasphenoid teeth in a 

 single patch. Nostrils extremely large. Toes five. 



Mexico. 



1. Thorius pennatulus. (Plate III. fig. 2.) 



Thorius pe nnatulus, Cope, 11. cc. 

 Head small, longer than broad ; snout truncate ; loreal regions 

 high, nearly vertical ; nostril elliptical, oblique, extremely large. 

 Body cylindrical, elongate, nearly four times the distance from tip 

 of snout to gular fold. Limbs weak ; digits rudimentary. Tail 

 stout, cylindrical at the base, slightly compressed distally, about 

 as long as head and body. Skin smooth ; no parotoids ; a distinct 

 gular fold ; thirteen costal grooves. Brown ; a dark lateral band, 

 whitish-margined above, commencing from the eye ; lower surfaces 

 unifoim or dotted with whitish. 



Total length 48 millim. 



From snout to cloaca 25 „ 



Head 5 „ 



Width of head 3| „ 



Fore limb 4 „ 



Hind limb 5 „ 



Tail 23 „ 



Mexico. 



a-c. Adult. Orizaba. 

 d-h. Adult. ? 



