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MUIUD^-SIOMODONTKS— IIUSl'KHOMYH AdHEOLUvS. 



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4703, from the Soutlicrn Stiitcs, prol)al)Iy Georgia, the under ]mr(s- nre not 

 white at III!, nor even whitisii, but cinnamon, only a iittlt; paler lluiii tin; sides. 

 No. 981 has quite a l)hick stripe alon^r tlie i)aei\. No. 2D(i 4, ironi Illinois, is 

 interesting in several respects. In the lir.st place, the feel are reinarknltly 

 small, less tiian in any Ilesperonn/.t we have seen, except mkhiganeiiniii ; and 

 in some other respects, especially ^'bitccis Jltrviii", it corresponds better with 

 Audubon and Baehman's descripti<m of Jiiicliiganem.is than the specimens we 

 have referred to that species do. The under parts, moreover, are white. The 

 general color of the upper parts, while showing unmistakalde traces of the; 

 ])eculiar orange shade of aureolas, arc much watered with a darker hue. This 

 is another case of darker hue in Illinois rodents than elsewhere; for the 

 Arvicola ripnrius, Pitymys pinetorum, and Hesperoinys kucopus, nil siiow this 

 peculiarity. A Saint Louis, Mo, skin might be referable to this species with 

 a shade of doubt, were it not acconipanietl by a little suckling one, possibly 

 its offspring, which settles the case, and at the same lime confirms the valid- 

 ity of the species in a very satisfactory way. This little creature is of the 

 same bright orange-cinnamon as the ailults, while, as is well known, the young 

 of leucopus arc, for some months, of a dark ashy-gray. 



I only venture to include in this series a specimen (No. 548) from the 

 Schuylkill River, Pa., with grave doubt. The animal appears to have been 

 skinned out of alcohol, and the yellowish tinge of the under parts may be 

 due to discoloration. In other respects, it is more like leucopus than aureolns, 

 having dusky ears, sharp line of demarkation along tiie sides, &c. 



Doubtlesi?, after all, there ore some who would prefer to consider H. 

 auroleus as a "permanent variety" of leucopus, but they need to be reminded 

 that such course wouhl remain simply a petiiio principii until tli'-y explain 

 the difference between a "permanent variety" and a "species". 



The figure and description of Arvicola nuttalli, Hari.an, agree very well 

 with the present species ; but, as they represent a l)riglit-colored leucopus 

 quite as well, and contain notliing positively distinctive, I agree with Mr. 

 Allen that it is not necessary to supersede the well-known and very expressive 

 name aureolxu. 



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