Expedition to the Eastern Canary Islands. 281 



The following is a summary of the only four specimens in 



England : — 



Wing. Culmen. Tarsus, 



mm. mm. mm. 



a. ? (type) 250 79 52 



b. ^ 259 77 49-2 



c. ? 257 81 52 



d. S (figured) 262 72-5 54 



a. E. Canary Is., 7. iv. 88, Coll. E. G. B. M.-W. Skin in the 



British Museum. 



b. E. Canary Is., 6. iv. 90, Coll. E. G. B. M.-W. Skin in the 



Liverpool Museum, 



c. E, Canary Is., 6 iv. 90, Coll. E. G. B. M.-W. Skin in the 



British Museum. 



d. E. Canary Is., 1913, Coll. D. A. B. Skin in the Tring 



Museum. 



The average measurements of the typical South African 

 species, H. niger niger, are : — Wing : ^ 285, $ 275 ; 

 culmen : ^ 69, ? 71 mm. 



In all species of Oystercatcheir the male has the culmen 

 somewhat shorter than the female. 



The occurrence of this rare Black Oystercatcher in the 

 eastern Canary Islands has been known for many years, as 

 will be seen by reference to the synonymy, it having been 

 mentioned by every writer on the group. Unfortunately 

 very little is known as to its habits in the islands, and how 

 it worked its way up the African coast and finally crossed 

 to the Canary Archipelago and there became resident and 

 modified, is still wrapt in complete mystery. At the present 

 day its nearest ally, Hamatopus niger niger Temm., inhabits 

 the coast and islands of Cape Colony, from which species 

 Hcematopus niger meadewaldoi has become evolved. It has 

 been said that there is a Black Oystercatcher on the coasl 

 of Gaboon, but very little evidence of the fact seems to be 

 forthcoming. It is true that an enormous part of the 

 African coast-line is quite unknown, and it would not be 

 surprising to find an allied form whose habitat is yet 

 undiscovered. 



