370 Illinois Slate Laboralonj of Natural History. 



5(4) Two distinct plantar tubercles. Color brown or black, 

 with numerous yellow spots; these generally aggre- 

 gated on the sides of the belly A. tigrinum. 



6 (3,1)) Costal grooves eleven 7 



7 ( 8) With a series of round yellow spots on each side, Im- 



maculate below. Large A. punctatum. 



8 ( 7) With transverse gray bands on tl e back. Rather 



small and stout A. opacum. 



9 (3,0) Costal grooves ten. Palatine series of teeth convex 



backwards. Color blackish brown, uniform or with 

 a few gray specks on the sides A. talpoideum. 



Amblystoma microstomuin, Cope. 



Amblystoma microstomum, Cope, Proc. Acad. Nat. Sci. Phila., 



1861. p. 123; Proc, Acad. Nat. Sci. Phila., 1867, p. 206. 

 Amblystoma porphyriticum, Hallowell, Proc. Acad. Nat. Sci. 



Phila., 1856, p. 8. 

 Amblystoma microstomitm, Smith, Tailed Amphibians. 1877, p. 



44 — Boulenger, Cat. Batr. Sal. in Coll. Brit. Mas., 21 ed.. 



1882, Sal. Caudata, p. 50. — Davis and Kice, Bull. 111. State 



Lab. Nat. Hist., I., No. 5, 1883, p. 11 



Total length from four to six inches. With thirteen cos- 

 tal folds. Body slender for a meml)er of this genus. Head 

 very small, strongly convex aliove and sloping uniformly from 

 the occiput to the margin of the snout. Eye small and well 

 forward. Gape small, lower jaw distinctly projecting beyond 

 the upper when the mouth is open. Tongue but slightly free 

 at its lateral margins, with a median longitudinal groove from 

 which the plicae radiate. Palatine series of teeth contiguous 

 at the middle line and forming an ol)tuse angle, the apex being 

 directed anteriorly; not extending beyond the inner margin of 

 the nares. Legs rather weak, digits depressed, the fourth toe 

 especially long. Tail sul)cylindrical at its l)ase, compressed 

 and gradually decreasing in depth distally. Superior surface 

 of head smooth; inferior surface and sides of tail granulate; 

 skin elsewhere minutely pitted. 



Color above and below dull black or fuscous, with numer- 

 ous grayish white patches on the sides, often contiguous and 



