J823.] On the Generation of the Opossum* 349 



Article V. 



Facts, Observations, and Conjectures, relative to the Generation 

 of the Opossum of North America. In a Letter from Prof. 

 Barton to Mons. Roume, of Paris, 



f (To the Editor of the Annals of Philosophy/,) 



DEAR SIR, Pcnkrrgare, Sept. 3, 1823. 



I RECEIVED from its author, the late Prof. Barton of Phila- 

 delphia, the enclosed printed copy of a letter which I have never 

 elsewhere met with, and it relates some circumstances which 

 have not been noticed by Sir Everard Home in his valuable 

 observations on the generation of the marsupialia in the Philo- 

 sophical Transactions for 1808, 1810, and 1819. 



The fossil remains of a species of didelphis are said to be not 

 unfrequently found in the Stonesfield slate, and I know of no 

 other animal belonging to either ofthe secondary or any older for- 

 mation which possesses the smallest claim to be called viviparous, 

 nor does even this family in its mode of generation, appear to be 

 . more than one of those links which connect the higher order of 

 viviparous with oviparous animals. 



In this point of view the Professor's letter becomes interesting 

 . not only to the zoologist, but in some degree to the geologist 

 also ; and I, therefore, offer it to you for insertion in the Annals 

 of Philosophy, I am, dear Sir, yours truly, 



L. W. DiLLWYN. 



DEAR SIR, PhUadelpUa, 



In looking over my list of correspondents, I find that I am 

 indebted tc you a letter. I cannot think of writing a mere 

 formal letter of apology, for my long silence ; and, therefore, I 

 shall contrive to send you something that may, at least, amuse 

 you. 



You and I have often talked together, and speculated, about 

 the generation of the Opossum of North America (the Virginian 

 Opossum of Pennant ; my Didelphis Woapink).^ I think I 



* There is not a little confusion concerning the nomenclature of the different species 

 of Didelphis, in the writings of Linnaeus, Gmelin, and other naturalists. See the arti- 

 cles " Didelphis marsupialis," and " D. Opossum," in the Systema Naturae, as pub- 

 lished by Linnaeus himself, and by Gmelin. I have, therefore, thought it most advisa- 

 ble to impose a new and more determinate name upon the animal, which has been the 

 subject of my experiments. The specific name of marsupialis is not very happily 

 applied to any particular species of Didelphis, since most of the species of this singular 

 genus are furnished with the marsupium, or abdominal sack. I object to Dr. Shaw's 

 specific name, Virginica (taken from Mr. Pennant), because it implies, that our Opos- 

 sum is restricted to, or especially common in, Virginia ; whereas this animal is nearly 

 equally common in every part of the United States (east of the Missisippi), from the 

 latitude of 40 to tliat of i?5, and even much further south. The name Woapinky which 



