A^ol. XXXV.] 2G 



" In the island of St. Thomas, which lies 150 miles 

 from the mainland, this feature is even more pronounced. 

 Exclusive of marine forms, we have a resident bird- 

 population of forty-six species, of which twenty-two species 

 (representing twenty - two different genera) are almost 

 certainly restricted to that island : — 



1. Onycognathus fulgidiis. 



2. Oriolus crassirostris. 



3. Hyphantornis grandis. 



4. Heterhyplmntes sancti-thom<e. 



5. Lagonostictaperreini thomensis. 



6. Neosinza concolor. 



7. Linurgus ritfohrunneus 



thomensis. 



8. Cinnyris neiotojii. 



9. Elaocerthia tlwmensis. 



10. Speirops luguhris. 



11. Zosteropsficedulinafece. 



12. Lanius newtont. 



13. Prinia moUeri. 



14. Twdus olivaceofiiscus. 



15. Amaurnciclila bocagei. 



16. Terpsiphone neiotoni. 



17. ChcBtura thomensis. 



18. Corythornis thomensis. 



19. Flammed Jlammea thomensis. 



20. Vinago sancti-thomcB. 



21. Cohimba arqiiatrix thomensis. 



22. Haplopelin simple.v. 



" Lastly, there is the little island of Annobon, very much 

 smaller in extent than either St. Thomas or Prince's Island, 

 and situated about 187 miles from Cape Lopez. Annobon 

 possesses only eight resident land-birds, and out of that 

 very small number four — Terpsiphone newtoni, Zosterops 

 griseovirescens, Otus capensis fea, and Haplopelia hypoleuca 

 — are peculiar to that island. 



"In addition to the species already mentioned, Estrilda 

 astrild souscB is restricted to St. Thomas and Prince's Is- 

 land; while Turturcena malherbei is found on Prince's Island, 

 St. Thomas, and Annobon. 



" The physical features of islands which hold such treasures 

 are worthy of particular notice, and I should like therefore 

 to draw your attention to Boyd Alexander's excellent de- 

 scriptive accounts of these three islands, which form the 

 introductions to my papers in 'The Ibis' {vide Oct. 1914, 

 et seq.). 



" The birds found on these islands belong, of course, 

 to strictly tropical African forms, the Gulf of Guinea lying 

 practically in the middle of the Ethiopian Region.'^ 



