3. OCEANODROMA. 347 



ChecJc-l. N. Atn. Birds, p. 104 {\SSV>) ■ Towus. Fr. U.>S. Nat. Mus. 

 xiii. p. 141 (1890). 

 Adult female. Dcark sooty-black, slightly glossy on the upper 

 surface, forehead and under surface browner : greater wing-coverts 

 ])aler ; under wing-coverts uniform sooty : bill, legs, and toes black. 

 Total length about 5-5 inches, wing 4-G5 ; tail, central rectrices 2-1, 

 lateral 1-6 ; bill 0-56, tarsus 0-87, middle toe 0*77, outer toe 0-73, 

 inner toe 0"6. 



Hah. \Yest coast of America from Lower California to Panama. 



fl. 5 ad. sk. Mazatlan, W. Mexico (A. Forrer). Salvin-Godman Coll. 



3. OCEANODROMA. „ 



Type. 



Oceanodroma, Reich. Ac. Syd. Nat. p. iv (1852) ; 



Coues, Proc. Ac. Pliil. 1864, p. 74 0. furcata. 



Cymochorea, Coues, Pr. Ac. Phil. 1864, p. 75 O. leucorrhoa. 



Range. Seas chiefly of the Northern Hemisphere, but southwards 

 to the coast of Peru and the island of St. Helena. 



Key to the Species. 



a. Plumage generally sooty-black. 



a'. Upper tail-coverts more or less white*. 



a". Base of the lateral rectrices black : longest 

 upper tail-coverts white, narrowly tipped 



with sooty leucorrhoa, p. 343. 



b". Base of the lateral rectrices white ; longest 



upper tail-coverts broadly sooty at the tip . crxjptoleucura, 

 V , Upper tail-coverts the same colour as the back, [p. 350, 

 not white, 

 c". Under wing-coverts uniform with the rest 

 of the under surface: 

 «'". Largest : wing I'o inches, tail 4'45 .... fuliyinosn, p. 352. 

 b'" . Smaller: wing 7 inches or less, tail less 

 than 4. 

 a*. Bill stouter, less elongated ; plumage 

 nearly uniformly dark. without plum- 

 beous tint melanin, p. 353. 



6*. Bill slender, more elongated ; mantle 

 and head more or less tinged -v\ith 

 plumbeous. 

 a'. Tarsus shorter (1 inch) ; head and 



mantle distinctly plumbeous inarhhami, p. 354, 



P. Tarsus longer (IT inch); head and 



mantle darker tristrami, p. 354. 



c'". Smallest: wing about 6 inches monorhis, p. 356. 



d" . Under wing-coverts much paler than the 



rest of the under surface homochroa, p. 355, 



b. Under surface white ; breast with suDtv collar . . hanilii/i, p. 356. 



c. Plumage generally pale ashy furcata, p. 357. 



* 0. macrodacfyla and 0. socorroensis apparently belong to this division ; but 

 as I have no specimens of either for comparison. I am unable to assign them to- 

 their exact position in the key. 



