150 



It is said to be very prolific, bringing forth three or four litters during 

 the summer, and, according to Audubon and Bachman, sometimes as 

 many as nine young have been found in one nest. They furnish an 

 important article of diet for the smaller carnivorous quadrupeds and 

 owls. 



Two Ohio specimens of this Mouse are in the museum of the Smith- 

 sonian Institution, one (young. No. 978) collected by Robert Kennicott. 

 I am ignorant of the exact locality where they were taken. 



— Another Genus of this sub family, Synaptomys, represented by a single 

 known species, S. cooperi, will probably be found to occur in Ohio, as it 

 has been discovered in an adjacent county (Franklin) of Indiana. 



It has the general appearance of an Arvicola, but the dental characters 

 differ, especially the incisor teeth, which have a longitudinal groove 

 near their outer edge. 



Genus Fiber Cuvier. 



Etymology : Latin — a Beaver. 

 1766. < Castor, Linn., Syst. Nat., i, 1766, 78. 

 1788. < Mus, Gm., Syst. Nat., i, 1788, 125. 



1792. X Myocastor, Kerr, "L. S. N., 1792 (type Myopotamm coypm)." 

 1800. ^^ Fiber, Cuv., Legons, i, 1800 (type Castor zihethicus). 

 1829. <:Levimus, Fischer, Syn., 1829, 289. 



1827. ^ Ondatra, " Lacepede." — Less., Man., 1827, 286 (type, Castor zibethi- 

 eus. 



Generic Characters. — Largest of the fa;mily. Form arvieoline, but tail 

 nearly as long as body without head, compressed, nearly naked, reticulate. 

 Hind feet set obliquely; soles naked, quadri-tuberculate ; toes incom- 

 pletely webbed. Fore arm bristle fringed. Muffle hairy, except the 

 nasal pad.-*. Ears small, with prominent angular antitragus. Whiskers 

 short. Pelage lanuginous, beset with numerous long, glossy hairs. 

 Mammte, six. Perineal glands highly developed. Dentition and skull 

 strictly arvieoline. Angular process of squamosal bone overhanging 

 orbit behind ; jugal, a mere splint, the squamosal and maxillary spurs 

 actually in contact. 



Fiber zibethicus (L.) Cuvier. 



MUSKRAT. 



1766. Castor zibethicus, Linn., Syst. Nat., i, 1766, 79, No. 3 (quotes Bris- 

 son,Kalm, Sarrazin). — Erxl., Syst. Reg. Anim., i, 1777, 444, No. 

 2.— Bodd., Eiench. Anim., i, 1784, 16a 



