AUKS, MURRES, AND PUFFINS 13 



a network of their burrows. When there is no soil to burrow in, 

 the birds use natural cavities. 



They reach the Farallone Islands the latter part of March, and 

 when the nests are made and incubation begun, Mr. Bryant says, 

 they may be located by the presence of a sentjnel at the entrance of 

 the burrow. 



The bright and oddly shaped bill, white eyes, and yellow nuptial 

 tufts, which flutter in the wind, give the bird a most distinguished 

 appearance. Its bill is not only an ornament but a most effective 

 weapon. When caught in its burrow the puffin inflicts painful 

 wounds with it, sometimes actually cutting to the bone, its jaws 

 remaining set until pried apart or until it is killed. 



GENUS CERORHINCA. 



16. Cerorhinca monocerata (Pali}. RHINOCEROS AUKLET. 



Bill much compressed, longer than deep; in breeding- season base of 

 bill surmounted by upright horn. Breeding plum- 

 age : upper parts dusky ; sides of head, throat, 

 and rest of under parts plumbeous, except for whit- 

 ish belly ; side of head with two series of white 

 pointed feathers. Winter plumage : breast more uni- 

 formly gray ; belly purer white ; horn absent. 

 Young : head without crests. Length : 14.00-15.50, 

 wing 7.25, bill from front edge of horn 1. 



Distribution. From coasts and islands of the north Pacific to Lower 

 California, and to Japan. 



When collecting the rhinoceros auklet at the Catalina Islands, Mr. 

 Joseph Grinnell found it a most persistent diver and powerful 

 swimmer under water. He did not see one of the birds on the wing. 

 They all dived on approach. He says the auklet is so short and 

 chunky that at a little distance it looks like a block of wood float- 

 ing on the water. The food of the birds Mr. Grinnell took, on ex- 

 amination of their stomachs, proved to be entirely a small yellow 

 crustacean, none of which were to be seen anywhere near the sur- 

 face. 



At Monterey Mr. Loomis saw an extensive migration of the auk- 

 lets on January 12, 1895. The birds came from the north in pairs, 

 and went on down the coast without stopping. 



GENUS PTYCHOBAMPHUS. 



16. Ptychoramphus aleuticus (Pall}. CASSIN AUKLET. 



Bill broader than deep at base ; upper outline nearly straight. 



Upper parts slaty black ; sides of head, neck, and throat plumbeous ; 

 spot on lower eyelid, and under parts, white. Length : 8.00-9.50, wing 

 4.75-5.25, bill .75. 



Distribution. Pacific coast of North America from Aleutian Islands to 

 Lower California. 



Egg. 1, unmarked, laid in a natural cavity. 



