500 



THE YAPOCK OPOSSUM. 



The general hue of the body is a pale fawn-gray, with a very watery look about it, 

 and set closely upon the skin. Four dark bands of sooty-black are drawn across the 

 body in a peculiar, but extremely variable manner. The first band extends over the 

 shoulders as far as the first joint of the fore limbs ; the second passes saddlewise across 

 the back, extending only half-way down the sides of the body ; the third passes over 

 the hinder quarters and traverses the greater portion of the thigh ; while the fourth is 

 reduced to a broad patch upon and above the insertion of the tail. Along the spine 

 runs a broad black band, which consists of three dark patches, and spreads into a wide 

 black patch upon the top of the head. The tail is dark for two-thirds of its length, and 

 white for the remaining third. 



In the young animal these peculiar markings are very strongly defined, for the pale 

 grayish-fawn becomes almost white, and contrasts powerfully with the dead, sooty-black 

 of the dark portions of the fur. 



On a closer examination of the structure of the Yapock, we come upon certain pecul- 

 iarities which distinguish the animal from any other of its relations, and give ample 

 cause for placing it in a separate genus, if not in a separate family. Intended for an 

 aquatic existence, and to gain its food in and about the waters, the Yapock is well 

 fitted for its course of life by the structure of its feet. The hind-feet are furnished with 

 a membranous web that connects the toes together as far as the base of the claws, and 

 serves as a paddle by which the creature may drive itself rapidly through the water, 

 or as a rudder by which it may direct its course. 



The fore-paws are endowed with great powers of grasping, and have a very hand-like 

 aspect. They are webbed only as far as the first joint. One peculiarity in their form 

 deserves notice. To a casual observer, the fore-feet of the Yapock appear to be furnished 

 with six toes, the superabundant member being devoid of a nail. So close a resem- 

 blance does this structure bear to a real toe that it has been described as such by a very 

 eminent naturalist. It is, however, nothing more than an unusual development of the 

 pisiform bone, which supports a fold of the skin. 



The under side of the feet is furnished with a large, rough, fleshy pad, and there are 

 also large, rough pads upon the toes. The claws are small and weak, and the thumb- 

 joint is not opposable to the others. The ears are moderate in size, sharp, and pointed, 

 and the head tapers rapidly towards the nose. The entire aspect of the creature is 

 aquatic, its elongated body and peculiarly shaped limbs being sufficient to proclaim it 

 a skilled swimmer even if its webbed feet were not taken into consideration. 



It is not a very large animal, its total length being only two feet, the head and body 

 measuring rather more than ten inches. In some specimens the tail is more developed 

 than in others, and measures as much as fifteen inches in length. 



Another peculiarity of structure in the Yapock is the presence of large cheek-pouches, 

 apparently similar in their use to those of certain monkeys. It is supposed that the object 

 of these receptacles is to enable the animal to engage in a lengthened chase of the various 

 aquatic animals on which it feeds, and to lay them up in store until it returns to shore 

 laden with the produce of its watery toils. These cheek-pouches extend far backwards 

 along the sides of the mouth, and seem to be capable of containing a large supply of food. 



As may be supposed from its structure, the Yapock feeds principally on fish, aquatic 

 insects, crustaceans, and other water-loving creatures. Powers of climbing would be 

 useless for such an animal, and it is accordingly found that the Yapock is unable to 

 ascend trees, but, as if in compensation for this deficiency, is a most admirable swimmer 

 and diver. One of these animals was once taken in a fish " crawl," or conical basket, 

 which affords ingress to the fish but does not permit them to get out again. The Yapock 

 had evidently dived after a fish, followed it into the basket, and not being able to make 

 good its retreat, had been ignominiously captured. 



The residence of this animal is always near water, and is generally made in a hole that 

 is tunneled close to the water side. It is a very rare animal, and comparatively few 

 specimens have as yet been taken. On account of its aquatic propensities and the nature 

 of its prey, it has been taken for an otter, and has been described under the title of the 

 Demerara Otter. Buffon notices it under the name of Petite Loture de la Guyenne. It is 

 a native of Brazil, and is generally found by the banks of the smaller streams and rivers. 



