156 PATAGONIAN EXPEDITIONS: ZOOLOGY. 



on the two middle feathers, with a slightly darker subterminal ashy band. 

 Tail of twelve feathers, and square. With no gradation of the lateral 

 rectrices. 



Lower surface pure white except a clouding of ashy blue on the sides 

 of the breast. 



Legs bluish. 



Feet : Bluish toes and flesh-colored webs. 



" Younger birds may be known by a less decidedly cinereous or bluish 

 grey tinge of the upper parts ; which tend more or less strongly towards 

 brownish. The forehead is not pure white but mixed with about an 

 equal amount of brownish ash." (Coues, Proc. Acad. Sci. Philad. 1866, 

 p. 164.) 



Geographical Range. — Southern Oceans. [Pacific Ocean near Cape 

 Horn, lat. 50° SoutK, long. 90° West, May 20, 1840 (J. Gould), adult skin, 

 c, Coll. Brit. Mus.] 



On account of the specimen above cited, this species has been included 

 as one of the petrels properly of the Patagonian Coast. Its occurrence in 

 this region however in view of our present knowledge must be regarded 

 as rare, if not casual. 



The Blue Petrel was not observed by any of the members of the Prince- 

 ton Expeditions to Patagonia. The description is based on three repre- 

 sentatives of the species in the Collections of the British Museum of 

 Natural History. 



"Nests in deep tortuous burrows in hill sides near the sea. Egg is 

 single, ovoidal and dull white, without color-markings. In the specimens 

 measured, there is, however, as shown by the figures, the usual range of 

 variation in contour. They remind one, in size and shape, of the eggs 

 of a bantam hen. Shell is thin, homogeneous, and compact in structure, 

 presenting under the lens a finely granular external surface. First found 

 October 23." (Natural History of Kerguelen, J. H. Kidder, M.D., Bull. 

 No. 3, U. S. Nat. Mus. p. 17, 1876.) 



