Mr. R. F. Tomes on a new species of Opossum. 73 



Sp. diagn. — Minor : protuberantia sincipitali maris parva : late- 



ribus colli in utroque sexu plumosis. 

 Hab. In Africa Occidentali, accidentaliter in Europa Meridionali. 

 Mus. Brit. 



2. Plectropterus Ruppellii. 



Cygnus gambensis, Riipp. Orn. Misc. p. 12, fig. 1. — P. gambensis, 

 Denham and Clapp. Travels, App. p. 204 ; Hartl. Orn. West-Afr. 

 p. 246(partim) • Sclater, P.Z.S. 1859, p. 131, pi. 152. f. 1. 



Sp. diagn. — Major : protuberantia sincipitali maris maxima : 

 area rhombea ad colli latera nuda, carneo-rubra. 



Hab. In Africa Orientali et Centrali, in Dongola et lacu Tchad. 



Mus. Brit. 



The second species of Plectropterus, given by Stephens (P. mela- 

 nonotus, Shaw, Zool. xii. pt. 2, p. 8) and also met with by Denham 

 and Clapperton (App. to Travels, p. 204), is Sarcidiornis africana, 

 Eyton (Monogr. Anatidse, p. 103). 



January 24, I860.— John Gould, Esq., V.P., in the Chair. 



Description of a New Species of Opossum, obtained by 

 Mr. Fraser in Ecuador. By Robert F. Tomes. 



Didelphys Waterhousii, n. s. 



Fur rather long, soft, and of a cotton-like texture ; general colour 

 dark brownish-grey, tipped with rufous on the sides ; under parts 

 brownish-buff, with a stripe of yellowish-white along the centre of 

 the throat and breast. A black mark through the eye, to near the 

 end of the nose. 



Muffle of a broadly ovoid form, more deep than wide, the oval figure 

 truncated at the bottom, where the upper lip constitutes its base ; 

 notch of the upper lip, occasioned by the mesial groove of the muffle, 

 deep ; on either side of it, in the edge of the lip, a double cleft. A 

 horizontal depression passing through the centre of the muffle, serves, 

 with the vertical groove, to divide it into four divisions or quarters, 

 of which the two upper ones have a somewhat discoid form, and 

 project laterally over the nostrils, partially hiding them. The two 

 lower ones are marked, each with two oblique shallow depressions, 

 passing from near the centre of the muffle to its outer margins, near 

 the base. 



Ears broadly ovoid, hairy on their hinder surface, at the base only, 

 and of a dark brown colour, tinged with yellow at the auditory open- 

 ing. Feet of a pale fleshy-brown colour, suffused with exceedingly 

 fine short hairs, scarcely visible to the naked eye, but becoming 

 thicker and longer on the upper surface of the fore feet. Nails 

 small and nearly white, each with a tuft of straight hairs springing 

 from their bases. 



Tail of a uniform dark brown colour for the whole of its length*, 



* Such is the appearance of the tail after being skinned and immersed in spirits; 

 but Mr. Fraser's note of this animal is to this effect : — " Nose and feet pale flesh- 

 colour, ears and tail a little darker." The young have the terminal two-thirds of 

 the tail of this colour, after having been skinned and sent home in spirits. 



