MAMMALIA. GLIRES. Beaver-Rats. 225 



XXVI. MURINE QUADRUPEDS.— 25. MUS. 24. 



The upper fore-teeth are wedge-fhaped : la general there are 

 three, feldom two, grinders on each fide of each jaw. Is 

 provided with complete clavicles, or collar bones. 



The animals of this genus are in general very fwift, and climb trees or walls with great readinefs ; 

 And ibme of them fv/im very well. They moftly dwell in holes, fome of them digging burrows in 

 the ground, while others fatisfy themfelves with the fhelter of chinks in rocks or walls, or under 

 ftones, or any concealment that occurs by chance. They generally keep in their retreats all day, 

 and go out during the night in queftof food, which is chiefly vegetables of different kinds; and, 

 when feeding, they fit up, and carry their food to the mouth in their fore paws. The females have 

 moftly eight teats, and breed feveral times in the year, having numerous litters each time. The 

 ears are moftly fhort and rounded ; and, in general, the fore paws have four toes, with a warty 

 fiibftance, or callofity, in place cf the thumb or fifth toe. Several of the fpecies emigrateat par- 

 ticular feafons of the year. 



The word Moufe, in the Englifh language, 'being exclufively appropriated to fome of the fpecies 

 cif this genus, and Rat, which is employed by Mr Pennant as the generic term, being in the fame 

 predicament, it was judged better to ufe a compound term for the genus, than rigidly to adhere to 

 the Latin term of Linnaeus. In imitation of the method adopted by Dr Gmelin and Mr Pennant, 

 the genus is divided into feveral lections, to which, befides a kind of fubgeneric character, collective 

 names have been affigned, which, it is hoped, will be found very convenient for diftinguifhing the 

 fpecies of this very numerous genus. — T. 



* B E A V E R-R A T S.— M T C A S T '0 R E S. 



The tails of this divifion are flattened laterally at the ends. 



4j8 1. Webbed Beaver- Rat. — 1. M. Myocaflor Coypus. 1. 



The tail is thick, hairy, of a moderate length, and fomewhat flattened ; the hind feet 

 are webbed. Molina, hift. nat. Qui. 255. 



Inhabits Chili. — Frequents the water, and has a ftrong refemblance, both in colour and fhape, to the 

 Otter ; but, in the number and arrangement of its teeth, it refembles the- Murine animals, having only 

 two grinders on each fide of the fore-teeth in each jaw. All the feet have five toes. The female 

 brings five or fix young ones at each litter. 



459 2 - Mufquafh.— 2. M. Myocajlor zibethicus. 2. 



The tail is long, flattened, and fharp pointed j the feet are not webbed. Schreber, iv. 



638. t. clxxvi. 

 i Vol. I. F f Caftw 



