GAVi^. 279 



The Marbled Guillemot can never be confounded with its shorter- 

 billed ally. These two very distinct species differ in the following 

 particulars : — 



Alca marmorata. Alca brevirostris. 



Bill from frontal feathers "8 to Bill from frontal feathers '5 to 



"7 inch. '4 inch. 



Tail-feathers all brown. Outer tail-feathers white. 



No white on any of the secon- White at tips of many outer se- 



daries. condaries. 



Lores always brown. Lores white in winter plumage. 



Under wing-coverts principally Under wing-coverts always grey. 



white in winter plumage. 



The changes of plumage are very similar in both specieSj but the 

 larger-billed form often has much white on the under wing-coverts 

 in winter, which is not the case in any winter examples of the 

 smaller-billed form that I have seen. 



274. ALCA BREVIROSTRIS. 



(KITTLITZ'S GUILLEMOT.) 



tiria brevirostris, Vigors, Zool. Joiirn. 1828, p. 357. 



Kittlitz's Guillemot may always be known by its very small bill, 

 which measures less than half an inch from the frontal feathers. 



Figures : Turner, Nat. Hist. Alaska, Birds, pi. 2 (winter plumage) ; 

 Henshaw, Nat. Hist. Coll. Alaska, Birds, pi. 1 (summer plumage). 



No authentic instance of the occurrence of Kittlitz's Guillemot, 

 otherwise known by the name of the Short-billed Marbled Guillemot, 

 in any of the Japanese Islands has been recorded. All the examples 

 recorded as Brachyrhamphus kittlitzi from the Kurile Islands or 

 Japan have proved on examination to have belonged to the longer- 

 billed species, Alca marmorata. There are, however, in the Pryer 

 collection two examples in nearly full summer plumage, obtained by 

 Mr. Snow on the Kurile Islands, which belong to the short-billed 

 species. 



Kittlitz's Guillemot appears to be a very rare bird. Besides the 

 two examples collected by Mr. Snow on the Kurile Islands, two 



