sa 
303 
Mr. Sclater exhibited a male example of the Bimaculated Duck of 
Yarrell and other British authors, which was now generally believed 
to be a hybrid between Anas boschas or Dafila acuta and Querque- 
dula crecca. It was shot when in company with other ducks (Anas 
boschas) on the Beauly Firth, Inverness-shire, in January 1860, by 
Mr. W. Lautour. 
Prof. Macdonald exhibited diagrams illustrative of, and made re- 
marks upon, a new scheme of zoological classification. 
The following papers were read :— 
1. ApprT1IOoNAL Note on D1IDELPHYS WATERHOUSII. 
By Rosert F. Tomes. 
Since the publication, in the ‘ Proceedings’ of the Society, of the 
description of this species, I have had occasion to study the descrip- 
tions of several species of Opossums in the ‘ Fauna Brasiliens*’ of 
Prof. Burmeister, and find that he has characterized, under the 
name of Grymeomys scapulatus, an Opossum, which he considers 
identical with the unnamed species described by Mr. Waterhouse at 
page 505 of his work on Mammalia. Believing in the identity of the 
specimen from Ecuador with the one from which Mr. Waterhouse’s 
description was taken, and supposing it to be without a name, I called 
it, in honour of its first describer, Didelphys waterhousii. The 
question for solution is, whether Prof. Burmeister and myself have 
referred the same species to this description by Mr. Waterhouse, or 
whether two distinct species have not been thus confounded by us. 
In the first instance, my name would have to give way, that of Prof. 
Burmeister having the precedence by three years; in the latter case, 
both names would remain. I submit the following as an explana- 
tion:—The specimen from which Mr. Waterhouse described was a 
male, and we have therefore no precise evidence of the nature of the 
pouch, although it is placed by him in that section in which the 
* ‘ Erlanterungen zur Fauna Brasiliens,’ &c., in folio, with plates, Berlin, 1856. 
