510 Zoological Society. 



might probably be identical with the one noticed by Bosraaii under 

 the name of Kokeboe ; but added, that tlie notice given of it by that 

 tra^AjUer was not sufficiently precise to admit of its being determined 

 with certainty. 



A specimen was exhibited of the Chironcctes Yapock, Desm., on 

 which Mr. Ogilby remarked as follows. 



" I am indebted to Mr. Natterer for the opportunity of examining 

 this rare and curious animal, of which he brought various specimens 

 from Brazil. That now exhibited is a male, and possesses the same 

 anomaly in the generative organs which characterizes the rest of the 

 Marsupials. I have not seen the female, but Mr. Natterer informs 

 me that the abdominal pouch is complete. The species is found in 

 all the smaller sti'eams of Brazil, and appears to extend fi-om the 

 southern confines of that empire, to the shores of the Gulf of Hon- 

 duras ; BufFon's specimen came from Cayenne, and a skin was re- 

 cently obtained by Mr. W. Brown Scott, labelled ' Demerara Otter.' 

 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 over 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 body; it measured 10 inches 

 in the foiToer 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 (Didelpkis); and I am at a loss to reconcile my omti 

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

 in ' Les Dents des Mammiferes ' p. 73, unless bj^ supposring 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 number 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 Opossu7ns. The first of the 

 upper jaw is longer than it is broad, and has four sharp 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 Cartdvora. In the 

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

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

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

 centre, and a smaller on each side. 



