FAUNA AMERICANA. 143 



da ; it is as large as the ordinary stature of the 

 Norway rat, and equally troublesome ; infesting 

 houses, but gives place to the Norway rat. 



Inhabit Florida and the borders of Mississippi 

 river. Two prepared specimens in Philadelphia 

 Museum; one from Florida, presented by Mr. 

 Ord, the other from Mississippi, presented by 

 Maj. Long's exploring party. 



A beautiful figure accompanies Mr. Ord's de- 

 scription of this animal, in vol. 4 of the Journal of 

 the Philadelphia Academy of Natural Sciences.* 



* Since this work went to press, we have received No. 1 1 

 of the Journal of the Academy of Natural Sciences, in time to 

 follow up the eventful history of this animal. In vol. 4, p. 345, 

 of the work above quoted, there is an essay entitled " A New 

 Genus of Mammalia, &,c. proposed by T. Say, andG. Ord ; read 

 March 8, 1825." The name of the proposed genus is " JVeo- 

 tomaP There appears to have been some mistake relative to 

 the date, wherein it is stated that the new genus " Keotoma''' 

 was proposed ; at any rate, it is very certain that on the evening 

 of the 8th of March, the identical animal on which this new 

 genus is founded, was described by those gentlemen as an " Ar- 

 vicola,'''' and this after an attentive examination of the teeth. It 

 was not until this description of the " Jrvicola Jloridanus'^ had 

 passed through the press, that it was recalled by the authors, 

 and the new name substituted. In order to avoid confusion, it 

 will be necessary for naturalists to remember that the animal 

 under notice, is at present described as pertaining to three or 

 four distinct genera. The first notice of this animal, is an im- 

 perfect description by Mr. Ord, in the Bull, de la Soc. Philom. 

 1818, who named it '•'■ Mas jioridamis,'''' (its identity with the 

 genus Mvs. uas doubted from the first, by the French natural- 



