278 Notes on Mr. R. B. Sharpens Catalogue of Accipitres. 



which I suggest the subgeneric name Dissodectes, indicating 

 thereby the peculiarity of their double-toothed mandible, 

 a feature in which they resemble the Harpagi of South 

 America/^ 



This peculiarity, however, is by no means a constant cha- 

 racteristic of the subgenus Dissodectes : although observed 

 by Mr. Sclater in D. dickinsoni, it is not present in all speci- 

 mens of that species ; and though distinctly indicated in 

 MM. Milne-Edwards and Grandidier's figure of the adult of 

 D. zoniventris *, an immature specimen of that species in the 

 Norwich Museum has the hinder tooth merely represented 

 by a slight sinuation. Such is likewise the case in two speci- 

 mens out of three of D. dickinsoni in the same collection, 

 whilst in the third the hinder tooth is absolutely wanting, as 

 it also is in all the examples (three in number) of D. arde- 

 siacus which are there preserved. 



The colour of the iris in the birds of this subgenus seems 

 also to be somewhat variable, not only as between the diffe- 

 rent species, but in some instances even between different 

 individuals of the same species. 



Von Heuglin speaks of Z>. ardesiacus as "iride umbrina^^f ; 

 andBarbozaduBocage, on theauthority of Anchieta, describes 

 its iris as chestnut-coloured {" chatain ") %. On the same 

 authority he mentions the iris in D. dickinsoni as being 

 brown §, and elsewhere as chestnut- coloured ('^ castanho ^^) ||. 

 Dr. Dickinson described the iris of the last-named species 

 as " dark brown " *[[ ; but a specimen obtained by Dr. Miller 

 in the Zambesi country and preserved in the Norwich Mu- 

 seum was noted by the collector as having the iris " light 

 orange ; " and that this is not an impossible variation may 

 perhaps be inferred from the circumstance of the nearly 

 allied D. zoniventris being said by MM. Milne-Edwards and 

 Grandidier to have the iris '' d^un beau jaune '' "^*. 



Mr. Sharpe gives the habitat oi D. ardesiacus as " Western 



* Ois. de Madagascar, vol. i. pi. 10. t Orn. N.O.-Afr. vol. i. p. 34. 

 X Om. d' Angola, vol. i. p. 54. § Om. d' Angola, vol. i. p. 55. 



II 19th List of Birds of Portuguese West Africa, p. 3. 

 i Ibis, 1864, p. 305. ** Ois. de Madagascar, vol. i. p. 35. 



