Zoological Society. 215 



the present siDCcimen as a new species, but in the event of its ulti- 

 mately being considered distinct, he proposed that it should be called 

 Felis Darwinii. 



Mr. James Reid read some notes on several quadrupeds, also from 

 the collection of Mr. Darwin, including a new species of Opossum, 

 which he characterized as Didelphis hortensis. He also noticed a 

 very young specimen of the Viscache, Lagostomus trichodactylus of 

 Brooks. This example, not much larger than our common Rat, dif- 

 fers from the adult in wanting the ridge of stiff black hairs over the 

 eyes so conspicuous in old specimens, and in wanting also the 

 grooves on the teeth. 



Mr. Gould exhibited from Mr. Darwin's collection of Birds, a 

 series of Ground Finches, so peculiar in form that he was induced to 

 regard them as constituting an entirely new group, containing 14 

 species, and appearing to be strictly confined to the Galapagos 

 Islands. Mr. Gould believed the whole of these Birds to be un- 

 described, and remarked that their principal peculiarity consisted in 

 the bill presenting several distinct modifications of form, while the 

 general contour of the species closely assimilated. He proposed to 

 characterize them under the separate generic appellations of Geo- 

 spiza, Camarhynchus, Cactornis, and Certhidea. Their characters will 

 be found in No. xlix. of the Proceedings. 



Mr. Gould then resumed the exhibition of a portion of his own 

 collection of Birds from Australia, and characterized as a new spe- 

 cies Hemipodius melanogaster, the characters of which are given in 

 the Proceedings. 



Mr. Gould also exhibited a new and interesting species of Parrot, 

 presented to the Society by Mr. John Leadbeater, and which he cha- 

 racterized on behalf of the donor, a.s Platycercus Ignitus, its characters 

 being given in the Proceedings. 



January 24, 1837. — Mr. Gould exhibited the 'Raptorial Birds in- 

 cluded in the collection recently presented to the Society by Charles 

 Darwin, Esq., and after some general observations upon the geogra- 

 phical distribution of the known species, proceeded to characterize 

 the following as new to science : 



PoLYBORUs galapagoensis. 



Were I not assured by Mr. Darwin that the habits of this bird 

 strictly coincide with those of the Caracara {Polyhorus Brasiliensis), 

 its mode of flight and cry being precisely the same, I should have 

 been induced to regard it as rather belonging to the genus Buteo 

 than to Polyhorus ; but as I have satisfactorily ascertained by a 

 close investigation, it forms a beautiful intervening link between 

 these genera, as is evidenced by the scaling of the tarsi and the 

 produced form of the beak; while its habits place it within the 

 limits of the latter genus. 



It is on the authority of Mr. Darwin also that I rely for the as- 

 surance of the two birds above described being the male and the 

 female of the same species, so great is the difference between them 

 both in size and colour. 



