338 CANADA POUCHED RAT. 



has been observed as far to the north as lat. 52". It abounds in Michi- 

 gan and Illinois. Farther to the south it extends along the western 

 prairies, and it was observed near the shores of the Platte, Arkansas, 

 Canadian, and Red Rivers, to. lat. 34°, and probably ranges still further 

 to the south. 



There are pouched rats in Texas and Mexico, but we are at present 

 unable to determine whether they are of this species. 



GENERAI, REMARKS. 



The first naturalist who gave a specific name to this Pouched Rat was 

 Dr. Shaw, in the Linnsean Transactions, accompanied by a figure repre- 

 senting it as having only three toes. The drawing had been made by 

 Major Davies. Subsequently (in 1801) he again described and figured it 

 in his General Zoology, vol. ii., p. 100, pi. 138. The pouches in both cases 

 are inverted, and hanging down like long sacks on each side. These 

 would be very inconvenient, as the animal could not place its nose on the 

 earth or fill its sacks, with such an unnatural appendage dangling at its 

 mouth. The error seems to have originated from the whim or ignorance 

 of an Indian. It is recorded, that in 1798 one of this species was pre- 

 sented by a Canadian Indian to the Lady of Governor Prescott. Its 

 pouches had been inverted, filled, and greatly distended with earth ; and 

 from this trivial circumstance an error originated which has been per- 

 petuated even to the present day. 



Rafinesque, who was either careless or unscrupulous in forming new 

 genera and species, and whose writings are so erroneous that we have 

 seldom referred to him, contributed to create still farther confusion among 

 the species of this genus. He arranged them under two genera. Geomys, 

 ■with cheek-pouches opening into the mouth, and Diplostoma, with cheek- 

 pouches opening exterior to the mouth. This last genus he characterizes 

 by its having no tail, and only four toes on each foot, (Am. Monthly 

 Magazine, 1817.) 



We consider it unfortunate that our friend Dr. Richardson should have 

 adopted both these genera, and given several species under each. We 

 have examined nearly all the original specimens from which his descrip- 

 tions were taken, and feel confident that they all belong to the genus 



PSEUDOSTOMA, of Say. 



In regard to the present species. Dr. Rich.ardson was undecided under 

 what genus it should be placed. The opportunities aflbrded us for mak- 

 ing a careful examination, leave no room for any doubt on that subject. 



That there are several species of pouched rats on both sides of the 



