January 24, 1837. 

 Rev. John Barlow, in the Chair. 



Mr. Gould exhibited the Raptorial Birds included in the collec- 

 tion recently presented to the Society by Charles Darwin, Esq., and 

 after some general observations upon the geographical distribution 

 of the known species, proceeded to characterize the following as 

 new to science : 



PoLYBORUS GALAPAGOENSis. Pol. intense fuscus ; primariis ni- 

 gris; secondariarum pogoniis internis albo etfusco transversim 

 striatis ; caudd cinerascenti-fuscd, transversim lineis angustis 

 et frequentibus intense fuscis notatd ; rostro obscure corneo; 

 pedibus olivaceo-Jiavis. 



Long. tot. 20 unc. ; rostri, 1^; ate, 141; caudcB, 9 ; tarsi, 3^. 



Foem. jun. Capite et corpore intense straniineis fuscoqtie variega- 

 tis ; illo in pectore et abdomine prcevalente ; primariis fusco- 

 nigris ; caudis rectriciim, pogoniis externis cinerascenti-fnscis, 

 internis pallide-rosaceis ; utrisque lineis angustis et frequenti- 

 bus fuscis transversim striatis, apicibus sordide albis ; rostro 

 nigrescenti-fusco ; pedibus olivaceo-jiavis. 

 Long. tot. 22 unc. ; rostri, 1| ; alee, 17; caudce, \0\; tarsi, 3^. 

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

 strictly coincide with those of the Caracara {Polyborus 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 Polyborus ; 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. 



Hab. In insulis Galapagorum. 



Polyborus (Phalcobsenus) albogularis. Pol. ficscescenti-niger, 

 marginibus plumarum inter scapulos fulvis ; primariis secon- 

 dariisque albo ad apicem notatis ; guld pectore corporeque stdttus 

 albis ; lateribus fusco sparsis ; rostro livido ; cerdflavd ; tarsis 

 olivaceis. 

 Long. tot. 20 unc; rostri, 1^; alee, 18^; caudce, 9; tarsi, 3. 

 Obs. I have somedoubts as to whether this bird may not eventually 

 prove to be a variety of Phalcobcenus montana, D'Orb. The prin- 

 cipal difference between this bird and the one described and figured 



