232 U. 8. P. R. R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT. 



DIDELPHYS, Linn. 



Didelphys, LINN. Syst. Naturae, I, 1735. 



While the genus Didelphys, in its widest sense, may be considered as possessing all the char 

 acters given under the family head, it is by some restricted to the species with the toes free, 

 and the fur of the back thickly interspersed with long coarser hairs. Of quite a number of this 

 particular group, but two belong to the United States north of Mexico these, at the same time, 

 being the sole North American representatives of the family. 



DIDELPHYS VIKGINIANA. 



Opossum. 



Didelphys rirginiana, SHAW, Gen. Zool. I, 1800, 473; pi. cvii. 



DESH. Mamm. I, 1820, 255. 



HARLAN, F. A. 1825, 119. 



GRIFF. Cuv. Ill, 1827, 24, pi IB. V, 1827, 186. 



TEMM. Mon. Mamm. I, 1828, 27. 



FISCHER, Syn. 1829, 263. 



WAGNER, Suppl. Schreb. II, 1841, 37. IB. V, 1855, 219. 



DEKAY, N. Y. Zool. I, 1842, 3; pi. xv, f. 2. 



WATERHOUSE, N. H. Mamra. I, 1846, 165. 



BACHHAN, Pr. A. N. S. 1848, 40. (Development) 



MICHEL, Ib. 46. 



AUD. & BACH. N. A. Quad. II, 1851, 107; pi. Ixvi. 



GIEBEL, Saugt 1855, 708. 



BDRMEISTER, Erlaut. Fauna Braziliens, 1856, 60; tab. v, vi, f. 1 and 3. (Skull.) 



Didelphys marsupialis, SCHREB. Saug. Ill, 1778; pi. cxlv.* (The description and plate cxlv, do not refer to the species.) 

 Virginian opossum, PENN. Quad. II, 1781, 301; pi. xxxiv. IB. Arctic Zool. I, 1784, 73. (Leverian Museum.) 

 Opossum, ST. HILAIRE & Ccv. Hist. Mamm. Ill, 1819; two plates. 



Sp. CH. Hairs whitish, with brown tips, imparting a dusky shade. Legs and feet uniform dark brown or black; the fingers 

 and toes white. Plead throughout yellowish white, chin and top of head scarcely darker. A dusky suffusion around the eye. 

 Tail shorter than the head and trunk. Body with long white hairs interspersed. 



Length to occiput, 5 inches; to root of tail, 20; of tail, 14J. 



In the above diagnosis I have presented the characters of this species sufficiently well for 

 comparison with the D. californica, which it so greatly resembles. According to Audubon and 

 Bachinan, the Hudson river is its eastern limit ; its western and southern are not defined. I 

 have not known with certainty of its existence far west of the Missouri, nor in Texas. 



