DIDELPHIS VIRGINIANA. 261 



One would suspect that this animal sleeps most part of the winter, as 

 it has such large quantities of fat both immediately under the skin, and 

 in the cavity of the belly, especially about the urinary bladder. 



Whether this description was taken from a large American opossum 

 or a small one, I do not remember ; but, by comparing it with one of 

 the small ones, I found them the same [vide Preparation No. 3759, 

 Didelphis opossum, Linn.]. 



The ears are thin, broad, and round, without any hair. The eyelids 

 are long, and much in the direction of the head : the pupil is round : the 

 cornea is much larger than in the human eye, in proportion to the size 

 of the eye : the tunica sclerotica is very thin. The teeth are most [like 

 those] of the dog, of any ; although they differ considerably, especially 

 the last grinders. The tusks are thinner than the dog's. 



The os hyoides is not attached to the head by bony continuity, nor 

 by ligament. 



The hind-feet are a mixture of the human hand and the foot of the 

 toed animals. The cuticle on the upper side of the toes is scaly, like 

 the tail. This form of foot is well adapted for climbing, as it can grasp 

 like the chameleon. The nails are similar to the dog's. The great toe 

 of the hind-foot is more of a thumb than a toe, as it is in many monkeys ; 

 but it has no nail upon it. The opossum walks upon the sole as far 

 as the os calcis, like the monkey, bear, &c. 



The male opossum has a small tendency to a pouch on the belly. 



The tail seems not to serve as a rudder for progressive motion, but to 

 serve for a fifth foot ; for the animal can coil it up in a very small com- 

 pass, and the skin is what may be called ' sealiform,' or like that of a 

 rat's tail: it has but little hair, excepting at the root: the scales are 

 similar to those of the beaver, only not so large. This is what is called a 

 ' cauda prehensilis.'' 



The hair of the body is of different kinds, according to its situation ; 

 on the trunk, neck, shoulder, and thighs, the hair is long, not thick, of 

 two kinds. On the legs it is shorter, stronger, and smoother, as also 

 darker ; there is but little on the feet, and none on the soles. The 

 colour of the skin varies : generally it is of a lightish grey, but is darker 

 in some parts, viz. on the legs and toes, and is white on the soles and 

 tips of the toes : it is of a dark grey colour at the attachment of the 

 scrotum. 



opossum, I found that she had just excluded from her uterus seven embryons, the 

 smallest of which scarcely weighed one grain, another barely two grains, and the 

 remaining five (taken together) exactly seven grains." — Barton in ' Annals of Philo- 

 sophy,' vi. (1823) p. 349. " Pacts, Observations and Conjectures relative to the 

 generation of the Opossum." See also my art. "Marsupialia," torn. eit. p. 320.] 



