228 Mr. D, A. Bannerman on an Ornithological 



Falconidce, 



Polj'boroides typiciis. 

 Elanus ceeruleus. 



Arcleicl(S. 



Butorides atrlcapilliis. 

 Ardetta sturmii. 



Cicomidce, 



Dissoura microscelis. 



€haradyiid<2. 



Oharadrius orbesi. 

 Pluvianus segyptius. 

 Stephauibyx inornatus. 

 Arenaria interpres. 



Scolopacidcs. 



Numenius arq^uatus. 

 N. pbseopus. 



Himantopus himantopus. 

 Totanus littoreus. 

 Tringoides hypolencus, 

 Calidris arenaria. 



Larid(B. 



Sterna maxima. 

 S. cantiaca. 



Rallid^, 



Porphyrio alleni. 



Columhid(s. 



ViDao'o calva. 



Xr. — An Ornithological Expedition to the Eastern Canary 

 Islands. — Part II. By David A. Bannerman, B.A., 

 M.B.O.U., F.R.G.S.* 



Anyone studying the Avifauna of the Canary Archipelago 

 is doubtless at once struck by the immense number of 

 geographical or insular forms which have been described 

 from these islands. Many well-known authorities are 

 inclined, without taking the trouble to investigate the 

 matter for themselves, to ridicule the idea that so many 

 subspecies can possibly occur there. I have therefore been 

 exceedingly careful to examine closely a series of every bird 

 on which there might rest the slightest doubt as to whether 

 it merits subspecific rank. In addition to this I have had 

 the very great advantage of studying the birds in their 

 native islands during the many delightful expeditions which 

 I have made in the last few years. The result of my in- 

 vestigations shows that a very large majority of the sub- 

 species described must unquestionably be ''^kept up.'^ 

 Naturally^ in these island-forms many different grades (if 

 such a word can be used of subspecies) occur side by side. 

 Take, for instance, the Slender-billed Barn Owl {Tyto flammea 



* Continued from p. 90. 



