AVIFAUNA OF LAY SAN. 53 



25. OCEANODROMA CRYPTOLEUCURA (Ridgw. 



HAWAIIAN STOHM-PETKEL. 



? Thalassidroma,s V .innominata, Dole, Proc. Boston Soc. Nat. Hist. xii. p. 308 (18G9) j id. Hawaiian Almanac, 

 1879, p. 55 (Hawaiian Is.). 



Cymochorea cryptohiicura, Ridgw. Proc. U.S. Nat. Mus. iv. p. 337 (1882) (Kauai) ; Eidgw. Water-B. N. Amer. 



ii. p. 406 (1881) (Sandwich Is.). 

 Oceanodroma cryptoleucura, Ridgw. Manual N.-Am. B. p. 71 (1887) ; Stejn. Proc. U.S. Nat. Mus. 1887, 



p. 78; Wilson, Av. Hawaii, pt. iv. pi. & text (Feb. 1893). 



Fuliginous above and below; the greater wing-coverts and outer webs of tertials paler, 

 inclining to ashy ; quills and tail-feathers sooty black, the latter (except the middle pair) 

 white at base ; upper tail-coverts white, the longest broadly tipped with blackish ; anal 

 region mixed with white. Total length about 8 inches, wing 5*75 to 8*3 ; tail very 

 slightly forked, the outer feathers 2'9 to 32 in length, the middle ones 02 to 0'3 shorter; 

 tarsus 0-85 to 0'9 ; length of bill from base of culmen 0'6. 



(Of my specimens the females have the largest measurements.) 



As the above synonymy shows, this rare species has until now only been known from the 

 Sandwich Islands. 



Tins little Petrel was only observed on French Frigate Island. According to Mr. Gay's 

 observations on Niihau, their habits are very similar to those of the European Storm-Petrel. 



