149 



November 13, 183S. 

 Professor Ovven, ia the Chair. 



A letter was read from G. Burghall "VVatts, Esq., Corr. Memb. 

 Z. S., addressed to William Yarrell, Esq., stating that a coUection 

 of specimens from the neighbourhood of Turbaco, South America, 

 was on the way to England for the Society's Museum. 



A letter from Alexander Gordon, Esq. was also read, begging the 

 Society's acceptance of the animal described by Mr. Waterhouse 

 under the name of Myrmecobius fasciatus, and also the Perameles la- 

 gotis. Both of these animals, Mr. Gordon stated, \vere from S\van 

 River and not from Van Diemen's Land as had been supposed. 



A paper entitled " Observations on certain modifications observed 

 in the dentition of the Flying Opossums (the genus Petaurus of 

 authors)," was communicated by Mr. G. R. "VVaterhouse. 



" In the ' Dents des Mammifires' of M. F. Cuvier, the dentition 

 of the Flying Opossums and that of the Phalangers is described 

 under the two heads 'Petaurus' and ' Phalangers proprement dits.' 

 Both the groups termed Petaurus and Phalangers by M. F. Cmaer 

 contain certain species of Flying Opossums, and like\vise species of 

 Phalangers. Those species, however, which have the flank-membrane 

 extended from limb to limb, enabling them to sail in the air likę a 

 parachute, are no\v \vith universal consent separated from the Phalan- 

 gers (Phalangista), and arranged under the generic title Petaurus or 

 Petaurista. 



" In grouping the Phalangers and Petaurists as above mentioned, 

 M. F. Cuvier was guided only by the characters ofFered by the den- 

 tition ; that of Petaurus Taguanoides certainly bearing a very close 

 resemblance to that of Phalangista Cookii. The teeth of Petaurus 

 sciureus, however, do not bear so close a resemblance to those of 

 Phalangista vulpina and P. maculata, although the three animals 

 mentioned are placed in the šame division by the author alluded to. 

 Regarding the Petauri as a distinct genus from the Phalangers, I 

 ■vvill proceed to describe their dentition as I find it in the skuUs before 

 me, w'hich I may observe consist of two specimens of each of the 

 foUovving species: — P. taguanoides, P.flaviventer, P. sciureus, and 

 P. pygmaus, and one skull of a new species hereafter described. 



" In these crania three distinct modifications in the dentition are 

 observable ; and as tliey are combined w'ith certain dift'ei'ences in the 

 škulis and in the external characters of the animals to which they be- 

 long, they may be regarded as forming three subordinate sections, to 

 which for convenience I shall apply the names, Petaurus, Belideus, and 

 Acrobata. T \vo of these names will be found in the ' Alammologie,' 

 by M. Desmarest. The dentition observable in the species of 



No. LXXI. — Proceedings of the Zoological Society. 



