370 Illinois State Laboratory of Natural History. 



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

 with numerous yellow spots; these generally aggre- 

 gated on the sides of the belly A. tigrinum. 



(3,0) 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 tVe back. Rather 



small and stout A. opacum. 



9 (3,6) 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 microstomum, Cope. 



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

 1861. p. 123; Free. Acad. Nat. Sci. Phila., 18()T, p. 20(). 



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

 Phila., 1856, p. 8. 



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

 44 — Boulenger, Cat. Batr. Sal. in Coll. Brit. Mus., 2d ed., 

 1882, Sal. Caudata, p. 50.— Davis and liice. 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 member of this genus. Head 

 very small, strongly convex above 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 plic;i' radiate. Palatine series of teeth contiguous 

 at the middle line and forming an obtuse 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 j)itted. 



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

 ous grayish white patches on the sides, often contiguous and 



