Ornithologists' Club. 437 



SULA WEBSTERI, Sp. U. 



Adult, in white plumage closely resembling S. piscatrix^ 

 having the same hoary-grey on the primaries, but at once 

 distinguishable by its dark brownish-grey tail ; the bill is 

 also more slender, and tlie red at the base of the mandible is 

 more extended. Young in grey plumage somewhat variable, 

 very different from the young of S. piscati'ix, being not so 

 dark above and the feathers of the back uniform brown, not 

 edged with light grey ; below darker than the young of 

 S. piscatrix. Size of S. piscatrix. 



Hub. Clarion Island, Galapagos, and the neighbouring 

 seas. 



NesOxMimus hulli, sp. n. 



Similar to N. melanotis, but with the buffy-white tips of the 

 primaries — and still more those of the secondaries — decidedly 

 wider, and with a distinct moustache-like line of black spots 

 from the base of the mandible to the neck. 



Culpepper Island. A good series. 



NeSOMIMUS AFFINIS, sp. n. 



Near N. parvulus from Albemarle, but easily distinguished 

 by its deeper, almost uniform dark brown upper surface and 

 the more heavily streaked sides of the body. Chest with a 

 more distinct brownish shade. 



Narborough Island. A small series. 



CeRTHIDEA BECKI, sp. n. 



Very closely allied to C. fusca Scl. & Salvin, from 

 Abingdon Island, but generally darker above and below, 

 especially the sides of the body and chest more brownish. 

 Bill in many — but not in all — specimens a little shorter ; 

 wing considerably longer, in males always above 55 mm. 

 (generally 57-58, never more than 58), in females about 

 54-55*5 mm. ; while in C. fusca the wing of the males does 

 not exceed 54 mm. in length, that of the females being only 

 50-52 mm. 



Wenman Island. A good series. 



