THE BIRDS OF THE PRIBILOF ISLANDS. 395 



and so I called the attention of the ten Aleuts in the boat to them and asked if they 

 also saw two birds. They all replied " Yes." Still there appeared something peculiar 

 about the birds, and I continued watching. Suddenly they veered off to the right, 

 and I instantly comprehended the situation. The upper one was really a gull, but the 

 lower was only its shadow thrown on a fog bank which was rapidly rolling down on 

 us. Only those who while lying becalmed at sea have seen a fog bank pass in between 

 them and the desired haven can appreciate the rapidity with which this occurs and 

 the solid appearance of the rolling, incessantly changing, aud compact-appearing mass 

 of the fog. It was on the upper surface of the front edge of such a fog bank that we 

 saw this shadow. The bank was moving but a very little slower than the gull, and 

 after the bird had veered off toward the land it was but a few moments before we 

 were enveloped, so that it was impossible to see little farther than our boat's length. 



These birds feed on pretty much everything in the way of offal. Even the dead 

 seals are soon devoured by them, and they vie with the foxes in their ability to search 

 out and dispose of all animal matter. Evidently the whole colony of this species 

 about St. Paul breeds and roosts during the summer on Walrus Island. 



The ground color of the eggs varies from light-drab gray to sepia, with very dark- 

 brown, sharply defined, irregular spots from the size of the head of an ordinary pin to 

 many one-fourth of an inch, and even one three fourths of an inch, in length. Two of 

 the eggs in a set of three have a few obscure spots, but the other has more than half its 

 spots obscured by the later deposits of egg lime. On one egg the spots are somewhat 

 streaked and penciled. Another set taken the same day, June 13, had two nearly 

 white eggs and one of the normal color. These white eggs are pale- bluish white, with 

 very faint spotting; no dark coloring whatever. The first set measure 2.80 by 2.15, 

 2.85 by 2.05, 2.86 by 2.07. The pale two are 3.05 by 2.11, and 3 by 2.15, the dark egg 

 having been broken. 



34. Iiarus barrovianus Kidgway. Point Barrow Gull. 



Larus ftorroBionns Eidgway, Auk, 1886,330; Man., 1896, 26. — ^Nelson, Bds. Alaska, 1887,51. — 



A. O. U. Ch. List, 1895, 16. 

 Lotus glcauoua, Saunders, Cat. B., Br. Mus. XXV, 1896, 289 (part). — CouES, Key, 1890, 741 (part). 



Among the hundreds of Larus glaueescens seen I collected one specimen of this 

 large pale gull on Walrus Island on June 13, 1890. It is the only one that I noticed. 

 It had three bare places on its lower underbody, thus indicating that it had been sitting 

 on eggs, though it was a male. Three eggs in the National Museum collection, taken 

 by Mr. Elliott June 4, 1873, and labeled St. Paul (but evidently from Walrus Island), 

 have been identified (perhaps wrongly) as belonging to this form. They measure 2.83 

 by2.10, 2.93 by 2, and 3.15 by 2.11. They are similar in color to the eggs of L. glaueescens, 

 though there is a slight tendency to blending about the edges of the spots. No. 118713, 

 ad. S , U.S.N. M. Walrus Island, June 13, 1890, W. P. Length, 31.50; extent, 63; 

 wing, 18.75 



35. Pagophila alba (Gnnn.). Ivory Gull. 



PlagopMla] ebwhea, Coubs, Key, 1890, 749.^Salvin, Cat. B. Br. Mus. XXV, 1896, 301. 

 Gavia alba, A. O. U. Ch. List, 1895, 15.— Eidgway, Man., 1896, 24. 



A northern species, perhaps a regular visitor in winter. One was taken by the 

 natives in February or March, 1895, and the specimen was afterwards secured by 

 Messrs. F. W. True and D, W. Prentiss. No. 151788, U.S.N.M. Wing, 12.88; tail, 

 5.28; culmen, 1.42; tarsus, 1.50. 



