124 MAMMALIA. 



Several of these animals have been sent to Europe from Van 

 Dieman's land, some of which have the belly white, and others fawn- 

 coloured, but aU of a deep brown above, with a long tail, which is 

 black at the base, and the posterior half white. They are sometimes 

 double the size of the brown rat. Hydromys leueogaster, and Hyd. 

 chrysogaster, Geoff. An. Mus. VI. pi. xxxvi. 



C A PROMTS, Desmar. 



The Houtias have four molars every where with flat crowns, the enamel 

 of which is folded inwards so that it forms three angles on the external 

 edge, and a single one on the internal edge of the upper teeth, and the 

 inverse in the lower ones. The tail is round and scantily philose ; they 

 have, like the rats, five toes to the hind foot, and four, with the rudiment 

 of a thumb, to the fore feet ; their form is that of a rat ; as large as a 

 rabbit or hare. Two species are known. 



Cap. foitrnieri Desmar., Mem. de la Soc. d'Hist. Nat. de Par. I. 

 1823. (The Congo Houtia)*. Muzzle brown; the under part of 

 the neck whitish ; tail brown, but half the length of the body. 



Cap. prehensilis, Pcessig. ; Houtia Carvalli. Less than the pre- 

 ceding ; browai, with a whitish throat ; tail red, as long as the body, 

 and partly naked at the end. Both species inhabit the island of 

 Cuba, and, together with the Agoutis, at the time of the discovery, 

 constituted the principal game of the inhabitants. 



Mus. Cuv. 



The Rats, properly so called, have three molars, of which the anterior 

 is the largest; its crown is divided into blunt tubercles, which, by being 

 worn, give it the shape of a disk, sloped in various directions ; the tail is 

 long and scaly. These animals are very injurious, from their fecundity, 

 and the voracity with which they gnaw and devour substances of whatever 

 kind. There are three species which have become quite common in our 

 houses, viz. 



M. musculus, L. ; Buff. VII, xxxix. (The Common Mouse). 

 Known in all times and at all places. 



M. rattus, L. ; Buff. VII, xxxvi. (The Black Rat). Of which 

 no mention is made by the ancients, and which appears to have en- 

 tered Europe in the middle ages. It is more than double the size of 

 the mouse, in all its dimensions. The fur is blackish. Several in- 

 dividuals have been occasionally found connected by the interlacing 

 of their tails; constituting what the Germans style the King of 

 Rats.f 



M. decumanus, Pall. ; Buff. VIII, xxvii. (The Surmulot, or 

 Common Norway or Brown Rat). ^Miicli did not pass into Europe 

 till the eighteenth century, and is now more common in Paris and 

 other large cities than the Black Rat itseK. It is larger than the 



* This is the Jsodon pilorides, Say. Zool. Journ. No. 2, p. 229. 



t See Bellerman on the King of the Rats (in German), Berlin, 1820. 



