FAMILY DIDELPHID®. 33 
and they are of very rare occurrence in any part of the world.* There are about fifty living 
species, distributed among ten or twelve genera, which have been described by differem natu- 
ralists ; but one only is found in the United States. 
GENUS DIDELPHIS. | Linneus. 
Muzzle pointed ; cars large and membranous. Internal toe of the hind foot opposable, with- 
out a nail. Tail half hairy and scaly. Teats varying in number, and placed within the 
pouch. Teeth, 48-50: Incisors, 1;° ; Canines, 2 ; Cheek teeth, =o 
THE AMERICAN OPOSSUM. 
DIDELPHIS VIRGINIANA. 
PLATE XV. FIG. 2. 
Virginian Opossum. PENNANT, Arct. Zool. Vol. 1, p. 73; Hist. Quad. Vol. 2, p. 18, pl. 63. 
Le Sarigue a oreilles bicolores. Cuvier, Régne Animal, Vol. 1, p. 172. Ed. prima. 
Didelphis virginiana. Harvan, Fauna, p. 119. Gopman, Am. Nat. Hist. Vol. 2, p. 7 (figure). 
Virginian Opossum. Griffith’s Cuv. Vol. 3, p. 24 (figure). 
Characteristics. Greyish white. Fur woolly, intermixed with long white hair. Ears black ; 
base and margin flesh color. Length two feet. 
Description. Head long and pointed, with the facial outline nearly straight ; long black 
bristles on the sides of the nose, over each eye and on the sides of the cheeks. Eyes oblique, 
and placed near the facial outline. Nostrils separated by a groove. Ears thin, membranous. 
Gape of the mouth wide, and exhibiting most of the teeth. Nails rather short, and curved 
on all the toes, except on the thumb or inner toe of the posterior extremities. In the figure 
given by Godman, this is represented as clawed, but his generic character asserts the con- 
trary. Soles of the hind feet furnished with large fleshy tubercles. Mamme or teats are, 
according to Desmarest, thirteen in number, and disposed in a circle around a central one ; 
according to Godman, there are eight on each side, which we suppose to be the normal num- 
ber. Tail enlarged at the base, where it is hairy for about four inches; the remaining part 
scaly, and covered with a few inconspicuous short rigid hairs. Fur of two kinds; a short 
woolly hair beneath, intermixed with longer and more rigid hairs, but all are very soft. 
Incisors ten above, the two anterior rather cylindrical, longest; an interspace between the 
incisors and the canine, which is compressed and pointed ; the first jaw tooth smallest, the 
four first compressed, the three last transversely broader. In the lower jaw, the eight inci- 
sors rounded and directed forwards, with no interspace between them and the canine. The 
cheek teeth with regular points, and not transversely dilated. 
Color. Greyish white, darker along the sides; on the face and abdomen, lighter grey. 
This color is produced by the intermixture of the short wool, which is white at the base and 
* BroperiP, Zool. Journ. Vol. 3, page 408. 
