138 PATAGONIAN EXPEDITIONS: ZOOLOGY. 



Back : Brown, except the upper tail coverts which are white, the cen- 

 tral ones having brown tips. 



Wing : Brown. The longer wing coverts white. Exposed portion of 

 quills brown, the shafts and inner webs white nearly to the tips. Inner 

 secondaries wholly white. 



Tail : White, each feather tipped with brown. 



Lower parts : White, except the throat which is pale brown, the feath- 

 ers having white bases. 



Under wing coverts and axillary feathers white. 



Bill dusky brown color. 



Tarsus yellowish brown. 



Feet like the tarsi, the outer toe browner. 



The female resembles the male in size and color. 



Geographical Range. — The Antarctic Ocean. 



The description is based on material in the British Museum of Natural 

 History. The birds were not obtained by the Princeton Expeditions. 



" TJialassoica aiifanfica is about as common, or uncommon, as the 

 preceding species [Fitlmayiis glacialoides) and is also comparatively easy 

 to capture. As a rule both these species keep farther from ships than the 

 abundant and tame Cape Pigeon [Daption capensis). Of the species 

 herein noted, TJialassoica antarctica appears to be the most exclusively 

 southern in its range. Going southwards Daption made its appearance 

 May 16, Fubuanis May 20, and Tlialassoica not until June 21." (Lucas, 

 Auk, IV. p. 4, 1887.) 



Genus PRIOCELLA Hombron & Jacquinot. 



Type. 



PrioceUa, Hombr. & Jacq. Compt. Rend. XVIII. p. 357 

 (1844); Jacq. & Puch. Voy. P61e Sud, Zool. iii. p. 

 148, t. 32, figs. 43-56 (1853); Salvin, Cat. Bds. 

 Brit. Mus. XXV. p. 395 (1896) ; Sharpe, Hand-List 

 Bds., I. p. 125 (1899) P. glacialoides. 



Thalassoica, Coues, Proc. Acad. Sci. Philad. 1866, p. 29 

 (Pt). 



