NATURAL SCIENCES OP PHILADELPHIA. 91 



Fuliginous brownish black, the rump and crissum white, the interdigital 

 membranes mostly yellow. 



Oceanites lineata, Bp. ex Peale. (Thai, lineata, Peale.) Much larger than 

 0. oceanica ; the colors genera'ly similar ; but the entire abdomen streaked 

 with black and white. Interdigital membranes wholly black. Wing 6.50 ; 

 tarsus 1.40. 



Oceanites Segethi, Coues ex Ph. et Ldbk. (Thai. Segethi, Ph. et Ldbk.) With 

 the form and general colors of 0. lineata; but the feathers of the neck and 

 breast uniformly slaty black, and those of the abdomen and crissum entirely 

 white, as are also the upper tail coverts, including the outermost row. 



Oceanites gracilis, Coues ex Elliott. (Thalassidroma gracilis, Elliot.) Much 

 smaller than lineata; "wing 5.22; tarsus 1.20." Sooty black; the rump, 

 upper tail coverts, and middle of a.bdomen white. Secondary coverts mar- 

 gined with light brown. Tail black ; two outer feathers partially white. 



II. Tail more or less emarginate, sometimes nearly even. Tarsal scuttellae 

 distinct. 



A. Toes exceedingly short and stout ; their webs small and narrow. 



VII. Genus Fregetta, Bp. Bill small, short, stout at the base. Third 

 primary nearly equal to second, first longer than fourth. Fuliginous and 

 white in color. 



F. tropica, Bp. ex Gould. (Thalassidroma tropica, Gould.) Very large, 

 nearly nine inches in length ; the tail more deeply forked than in other 

 species of the genus (f inch). Fuliginous black ; the abdomen, sides, under 

 surface of wings, throat and a nuchal collar white. 



F. grallaria, Bp. ex Vieillot. (Non grallaria, Licht. Proc. fregatta, Kuhl, 

 nee Linn. Thai, leucogaslra, Gould. Thai, oceanica (!) Bp. olim.) Deep 

 grayish, darkening on the wings and tail into brownish black. Middle of 

 belly, sides, and tail coverts white. Wing 6.25 inches from the carpal joint. 



F. melanogastra, Bp. ex Gould. (? Proc. fregata, Forst. nee Linn. P. gral- 

 laria, Licht, nee Vieill. Thai, melanogastra, Gould. Proc. melanogastra, 

 Schlegel. Rather smaller, but with slenderer and longer bill and feet ; and 

 the white of the abdomen divided by a longitudinal black line. 



F. Lawrencii, Bp, ex Lawr. (Thai, fregetta, Lawr. nee auct.) From the 

 South Atlantic coast of North America. Length about eight inches. Wing 

 6.00. Tail white at the base ; its terminal half and the whole of the median 

 rectrices black. 



B. Toes exceedingly long and slender, their webs broad and full. 



VIII. Genus Pelagodroma, Reich. Bill unusually long, weak, and com- 

 pressed ; the nasal tubes short, obliquely elevated. Proportions of primaries 

 about as in Fregetta. Tail very long, scarcely emarginate, the rectrices ex- 

 ceedingly broad to their truncated tips. 



Pelagodroma fregata, Bp. ex Linn. (Proc. fregata, Linn, sed nee auct. quae 

 plerunique ad species varias generis Fregettae spectant. Proc. marina, Lath. 

 Thai, marina, Gray. Pelagodroma marina, Reich. Proc. cequorea, Soland. 

 Proc. hypoleuca, Webb et Berth.) Interdigital membranes yellow. General 

 color grayish ashy, deepening into blackish on the wings and tail. Under 

 parts with the front and a superciliary ray white. 



The present paper will be followed as soon as possible by a similar review 

 of the section Puffineas. 



April hth. 

 Mr. Cassin in the Chair. 

 Eight members present. 

 1864.] 



