COTTON-RAT. 



229 



SiGMODON HispiDUM, Say and Ord, Journ. Ac. Nat. Sc, Phila., vol. iv., pt. 2, p. 354, read 



March 22d, l.s25. 

 Arvicola Hortensis, Harlan, Fauna, 1825, p. 138. 



" HispiDus, Godman, vol. ii., p. 68, 1826. 



" Hortensis, Griffith, Cuvier, vol. v., sp. 547. 



DESCRIPTION. 



In its general external appearance this species approaches nearer to 

 the genus Arvicola than to Mus. It has the thick short form of the former, 

 and the broad and rather long ears of many species of the latter. The 

 fur is long and coarse. 



Head, of moderate size, rather long ; nose, pointed ; whiskers, few, 

 weak, and shorter than the head ; eyes, of moderate size and rather pro- 

 minent ; ears, broad, rounded, and slightly covered with hair. 



Fore-legs, rather short and slender; four toes on each foot, the middle 

 ones nearly of equal length, the inner one a size shorter, and the outer 

 shortest ; there is also a rudimentary thumb, protected by a strong conical 

 nail. Hind-legs, stouter ; five toes on each foot, much longer than those 

 on the fore-feet ; middle claw longest, the two on each side nearly equal, 

 the outer, not one-third the length of the others, and the inner, which 

 rises far back, shortest of all ; nails, rather small, sharp, and slightly 

 arched ; toes, covered with hair extending to the roots of the nails ; tail, 

 clothed with short hairs. 



COLOUE. 



Hairs, on the whole upper surface of the body of a dark plumbeous 

 colour from the roots to near the extremities, edged with brown, and ir- 

 regularly tipped with black ; giving it a rusty reddish-brown appear- 

 ance. The ears, head, and tail, are of the colour of the back ; chin, 

 throat, and under surface of body, dull- white, the hairs being ashy-gray 

 at the roots, and whitish at the points. 



DIMENSIONS. 



From point of nose to root of tail 



Tail .... 



Length of ear 



Breadth of ear 



From eye to point of nose 



From point of nose to ear 



From heel to point of longest nail 



6 inches. 



4 do. 



i do. 



i do. 



§ do. 



n do. 



li do. 



