1883.] 411 [Brewster. 



lected mates of their own style among so many thousands of the 

 common kind, 1 for it is well known that with other birds ad- 

 dicted to dichromatism, or great variability, the different varieties 

 are quite as apt to be found paired with their opposite extremes 

 as with individuals of similar coloring. 



91. Lomvia arra bruennichi, Sen. — Briinnich's Guillemot. 

 We observed (or at least identified) this species only at Bird 



Rocks where it had been previously found by Bryant in I860 but 

 unaccountably overlooked by Maynard in 1872. At the time of 

 our visit it actually outnumbered the. Common Guillemot and re- 

 presented, according to the best estimate that I could make, 

 about seventy-five per cent of the total colony of Murres. 2 The 

 two species were more or less indiscriminately mingled on most 

 of the ledges and it was not unusual to see alternating pairs sit- 

 ting so close together that they touched one another. Under 

 these conditions it is of course difficult to identify any considera- 

 ble number of eggs, although a few may be positively determined 

 by using care and patience, for there is no trouble whatever in 

 distinguishing the birds at any reasonable distance. Tne whitish 

 tomiae of Brunnich's Guillemot afford a ready mark of distinction 

 when the bird is flying, and on the ledges its black head and neck 

 are conspicuous among the much lighter, chocolate-colored ones 

 of the Common Murres. 1 observed no difference in the flight or 

 habits of the two species, but more extended observations would 

 probably reveal certain distinctive traits. Mr. V^elch informs 

 me that Brunnich's Guillemot breeds sparingly at many places 

 along the southern coast of Newfoundland, but he did not find 

 the Common Guillemot there, although he looked for it carefully. 



92. tJtamia torda, Linn. — Razor-billed Auk. 



The Razor-bill, although less ubiquitous in the Gulf than the 

 Black Guillemot, is still more generally dispersed tnere than either 

 the Murres or Puffins. The largest colony which we visited was 

 at Bird Rocks, where there were probably several hundred pairs 

 nesting in crevices, or in the deserted burrows of the Puffin ; but 



1 Maynard's experience at Bird flocks was identical with mine. He found the 

 Kinged Murres invariably paired with individuals of their own kind. 



2 In 1860 Bryant estimated the comparative numbers of the three kinds of Murres 

 at Bird Bucks as follows: Three of N. troille to two of N. lomvia [L. arra briiunichi], 

 and one of U. ringvia. (See Proc. Bost. Soc. Nat. Hist., vol. vm, 1861, p. 75.) 



