20 REVISION OF AMERICAN MOLES— TRUE. vol.xix. 



Diagnosis of species. — Snout simple, depressed ; naked above as far 

 back as the line of the anterior incisors. Nostrils simple, superior, 

 with two minute papilliform processes within. Eye and auditory orifice 

 minute and concealed in the fur. Palm as long as the sole, but two 

 and one-half times as broad. Tail short, slender, and terete; the prox- 

 imal third clothed with long hair like that of the body, and the remain- 

 der with sparse, short hairs. Color brownish gray, varying to silvery 

 gray and to creamy buff. Hairs of feet and tail white. 



KEY TO SUBSPECIES OF SCALOPS AQUATICUS. 



a. Size medium (average total lengtli 162 mm.). Color sbiuiug gray-browu. 



tjjpictts, p. 20. 

 6. Size very small (average total length 142 mm.). Hiud foot long. Tail short. 

 Color as in a. Skull and teeth delicate; coronoid process slender, uncinate. 



austraUs, p. 21. 



c. Size very large (average total length 1110 mm.). Tail and hind feet long. Color 



inclining to silvery. Skull nuissive; molars large and quadrate ; coronoid process 

 triangular machriuiis, p. 20. 



d. Size very small, as in aitsiralis (average total length 139 mm.). Wrists and base 



of snout in males bright rusty orange. Skull and teeth massive, frontal sinuses 

 enlarged ; coronoid process stout texan us, p, 21. 



DIAGNOSES OF SUBSPECIES. 



SCALOPS AQUATICUS TYPICUS. 

 EASTERN MOLE, 



Diagnosis. — Average total length, 162 mm. ; tail one-sixth of the same, 

 and hind foot one-eighth ; dentition moderate; coronoid process of man- 

 dible heavy, scarcely uncinate, with a more or less distinct mammi- 

 form tubercle on the posterior margin; color nearly uniform shining 

 grayish hair-brown; grayer and more silvery below; all the fur of the 

 body plumbeous at the base; hairs of the feet and tail white. 



SCALOPS AQUATICUS MACHRINUS (Rafinesque). 

 PRAIRIE MOLE. 



Talpa machrina, Rafinesque, Atlantic Journal, lSo2, p. 61. 



Talpa sericea, Rafinesque, Atlantic .Journal, 1832, p. 61 (Young). 



Scalops argentafus, Audubon & Bachman, Joiirn. Acad. Nat. Sci. Phila., VIII, 



1842, p. 2U2. 

 Scalops aquaiicus aroentatus, CouKS, Bull. U. S. Geol. and Geog. Survey Terr., Ill, 



No. 3, 1877, p. 633. 

 ? Talpa Fennantii, Le Conte, Proc. Acad. Nat. Sci. Phila., VI, 1853, p. 327. 



Diagnosis. — Size the maximum for the species. Total length, aver- 

 age, 188.7 mm.; skull, average, 37.1 mm. Tail and hind foot jjropor- 

 tionally longer than in the tyjiical form. Teeth large. Coronoid ])roc- 

 ess of Tnandible triangular, large, with usually a straight posterior mar- 

 gin. Color as in the tj'incal form, or a little palei\ 



Average diincitsions from fresh specimens (6 from Illinois): Length 

 of head and body, 154.9 mm. ; tail vertebne, 33.8 mm. Average dimen- 



