Buller. — On a new Species of Petrel 215 



Mr. 



Sterna 



been actually obtained and examined it is impossible to admit it into our list 

 as a recognized species. Mr. Potts, in his original notice (t.c 9 p. 107), merely 

 described the bird as it appeared to him on the wing. He stated that the 

 whole plumage was white, and that " the bill appeared to be light-coloured," 

 adding that these "observations were made during its rapid movements." 

 He gave no hint whatever of its size, although he now refers to it as a "Jine 

 white Tern," as compared with the Little White Tern (Sterna nereis). 



On such a description as this I fear that Mr. Potts' claim to the discovery 

 of a new species would scarcely be admitted by ornithologists at home ; and 

 even if it were the name of Sterna alba has been preoccupied by Gmelin. The 

 bird may turn out, as Mr. Potts himself suggests, to be identical with a 

 species recorded from Norfolk Island. But if, on further acquaintance, it 

 should prove to be new, I think we cannot do better than associate Mr. Potts' 

 own name with it in lieu of the one he has proposed. 



Akt. XXVI. — Description of a new Species of Petrel (Procellaria affinis). 



By Walter L. Buller, D.Sc., F.L.S., etc. 



[Read before the Canterbury Philosophical Society, 28ih October, 1874.] 



In the Canterbury Museum I find the skin of a Petrel which appears to be 

 new. There is a ticket attached to it with the following memorandum, 

 "Shot — Potts River, 1872," and this is all the information I possess about 

 the specimen. It bears a general resemblance to Procellaria cookii, but has 



longer wings and shorter 1 

 may be due to immaturity. 



The type specimen of P. cookii y which was obtained off the New Zealand 

 coast, is in the British Museum. In this bird the wing measures from the 

 flexure to the tip 9-25 inches, whereas in the present species, although of 

 similar size, the wing measures 10*5, showing a difference of an inch and a 



differences 



quarter. 



length 



species it is scarcely visible. The plumage likewise differs in the following 

 respects. Instead of the whole upper surface of the wings being blackish- 

 brown, the secondaries and their coverts are ashy-grey narrowly margined with 

 white ; the feathers of the back and rump and the upper tail-coverts have 

 darker margins ; and there is far less white on the inner webs of the secondary 

 quills. The legs and feet, instead of being yellowish brown with paler webs, 

 as in P. cookii, are (so far as I can judge from the dried specimen) dull yellow 



