67 



Both this and Mr. Natterer's specimen agree with the figure and 

 description of BufFon, except that they are of a larger size, and in- 

 stead of a grey mark ovur each eye, have a complete band of that 

 colour extending entirely across the forehead. In Mr. Natterer's 

 specimen the terminal half-inch of the tail only is white ; in Mr. 

 Scott's on the contrary, the last 4 inches are of this colour : the 

 tail is exactly of the same length as the bodj'; it measured 10 inches 

 in the former specimen and 12 in the latter, but Mr. Natterer in- 

 forms me that he has other specimens which measure 14 or 15 inches 

 in length. 



"The teeth of this animal are altogether different from those of 

 the Opossums (Didelphis); and I am at a loss to reconcile my own 

 observations with those of M. F. Cuvier upon this subject, as given 

 in ' Les Dents des Mammif^res ' p. 73, unless by supposing that 

 there must have been some mistake about the skull referred by 

 M. Cuvier to the Yapock. For my own part, I could not be deceived 

 in this matter, as the skull which I examined had never been ex- 

 tracted from the specimen. The incisors and canines are of the same 

 form and numljer as in the true Opossums, the two middle incisors 

 above being rather longer than the lateral, those below broader and 

 a little separate. The molars are five on each side, two false and 

 three real, both in the upper and under jaws. The first false molar 

 is rather small and in contact with the canine, both above and be- 

 low: the second is half as large again, and both are of a triangular 

 form, with apparently two roots. The three real molars are of the 

 normal form of these teeth among the Opossums. The first of the 

 upper jaw is longer than it is broad, and has four sharjD elevated 

 tubercles with a low heel projecting backwards ; the second resem- 

 bles it in general form, but is larger and broader ; the third is small 

 and resembles the tuberculous molars of the true Carnivora. In the 

 lower jaw the three real molars do not materially differ in point of 

 size. They are narrower than those of the ujjper, have their tuber- 

 cles arranged in a single longitudinal series, a single large one in the 

 centre, and a smaller on each side. 



" The Yapock has very large cheek-pouches which extend far 

 back into the mouth, and of which the opening is very apparent. 

 This circumstance, hitherto unobserved by zoologists, throws con- 

 siderable light upon the habits of this rare animal, which thus ap- 

 pears, like the Ornithorhynchus, to feed upon freshwater Crustacea, 

 and the larva of insects, spawn of fishes, &c. which it probably stows 

 away in its capacious cheek-pouches. For 2 inches at the root the 

 tail is covered with the same description of fine close fur as the body; 

 from this part it tapers gradually to the point and is covered with 

 small scales, arranged in regular spiral rows, and intersj)ersed with 

 bristly hairs, particularly on the under surface, a fact perfectly con- 

 clusive against the generally received opinion of this organ being 

 prehensile in the Chironectes. Indeed, the tail so perfectly resem- 

 bles that of the Hydromys chrysogaster, even to the white tip, that 

 it would be impossible to distinguish these organs if separated from 

 the respective animals. The useless appendage of a prehensile tail 



