BIRDS FROM THE FARALLON ISLANDS. 31 



eggs are laid, their presence may be due to some extent to 

 accidental accumulation. When a bird leaves the nest, the 

 mate at once pursues, as though trying to drive her back, 

 chasing her along the ground, with upraised wings, mean- 

 while making the usual hissing noise, and following her even 

 out to sea. 



Upon each side of the abdomen of the specimens which 

 I have examined are bare spots against which the eggs are 

 held. 



Although noisy at most times, they are invariably silent 

 while sitting, differing markedly from the puffins in this 

 respect. In no place were two birds found occupying the 

 same cavity. If their eggs are taken, they will lay again 

 in the same place. 



Their food consists principally of fish, which they obtain 

 by their expert diving. 



Egg laying begins early in May aud continues into July. 

 Young in down were found July 16th, 1886. 



Twenty-five sets of two eggs each average 61.6 x 41.4 mm. 

 Selected specimens of the two extremes in size measure 

 66.5x41.5; 66x42; 64x43; 60x43; 60x39.5; 59.5x39.5; 

 58.5 X 41;5; 58.5 x 41 millimeters. 



4. Uria troile californica. 



Calefoknia Murre. — By far the most abundant species, 

 outnumbering all others combined. They begin to arrive 

 on the island in myriad numbers by the first of April, and 

 commence departing about the middle of September; by the 

 first of October they have all left the island but can be 

 seen upon the water. 



Their arrival usually occurs at night when great numbers 

 come suddenly, and perhaps leave the next day; especially 

 are they likely to leave soon after coming — and before 

 mating — if a storm occurs, returning of course later. 



The food of the murres consisted, as far as was learned? 

 wholly of fish. 



