PROCELLARIID.E — PROCELLARIIN.E: PETRELS. 1041 



family. Length under 10.00; wing 7.00 or less. Plumage in most cases fuliginous, unicolor 

 or relieved with white on the tail. A small group of 3 genera, all represented in North 

 America. They share with the long-legged Stormy Petrels (Oceanitincc) the anatomical 

 characters of lack of basipterygoids, even hind border of sternum, long manubrium of furcula, 

 and slender coracoids with little divergent axes, in these respects differing fnjm Fulmarincc and 

 P affinince ; they also agree with the Oceanitincs in the small size and general outward aspect, 

 but differ remarkably in the feet, as will be more particularly noted under head of the next 

 subfamily. The species are not numerous, and most of them belong to the genus Oeeanodroma. 



Analysis of Genera. 



Tall cuneate. Color entirely fuliginous. Lengtli under G.OO Halocyptena 



Tail square or a little rounded. Color fuliginous, with wliite upper tail-coverts. Lengtli under G.OO . ProceUaria 

 Tail forked. Color variable. Length over 6.00 Oeeanodroma 



HALOCYPTE'NA. (Gr. aks, hals, the sea ; wkvs, oJcus, swift ; ttttivos, ptenos, winged.) 

 Wedge-tailed Stoumy Petrels. Like a miniature Q^strelata or Bulweria ; unicolor, 

 fuliginous. Bill much shorter than head, about i the tarsus, weak and slender, acutely 

 hooked ; nasal tubes as in ProceUaria proper. Wings foldiug beyond tail, 2d primary longest, 

 3d nearly equal, 1st about equal to 4th. Tibia briefly bare below; tarsus little longer than 

 middle toe and claw; outer toe without claw as long as middle; tip of inner claw reaching 

 base of middle ; hallux minute; webs moderately full ; claws compressed, curved, acute. Tail 

 rather long, wedge-shaped; central feathers projecting; lateral regularly graduated, narrowly 

 rounded. One species. 



H. microso'iiia. (Gr. fiUpos, mikros, small; aSifia, soma, body.) Least Petrel. Adult: 

 Lustrous brownish-black, darker above, blackening on wings and tail, browning ou under 

 parts, graying on greater wing-coverts and inner quills ; bill and feet black ; no white any- 

 where. Length 5.75 ; wing 4.75; tail 2.50, graduated 0.35 ; bill 0.50; gape 0.62 ; height at 

 ba.se 0.19, width 0.21; nasal tube 0.22; tibia bare 0.30; tarsus 0.90; middle toe and claw 

 0.82 ; outer ditto 0.80 ; inner ditto 0.68. A queer little bird, from the coast (jf Lower California 

 to Panama. My type specimen, described in J864, remaiued unique till 1888, when the second 

 one was taken in the Bay of Panama (Pr. U. S. Nat. Mus. xiii, 1890, p. 141). Salvin cata- 

 logues one in the British Museum from Mazatlau, Mexico. In 1896 the bird was found breed- 

 ing witli Oeeanodroma melania and 0. socorroensis on San Benito Island off the Lower Cali- 

 fornia coast. Egg laid in July in a hole or crevice of rocks, not in underground burrow, 

 single, dead wliite, with the usual rosy blush when fresh and unblown, in many cases with a 

 ring of black specks at one or both ends, which come off at a touch, leaving only faint stains ; 

 shape variable, elliptical varying to long or short ovate: 0.97-1.07 X 0.70-0.77 (Axthonv, 

 Nidcdogist, Oct. 1896, p. 16). 



PROCKLLA'RIA. (Lat. procella, a tempest.) Square-tailed St()i;mv l'Kri:i'i..s. 

 " .Mother Carey's Chickens." Diminutive, fuligiuous, with white upper tail-coverts. 

 Bill small, sh(jrt, C(mipressed, sides rapidly converging to narrow tip ; less than half as long 

 as head, about ^ the tarsus. Wings folding beyond tail; 2d primary longest, 3d little sht)rter, 

 1st less than 4th. Tibia briefly bare below; claws compressed, curved, acute. Tail slightly 

 rounded or nearly square, with broad feathers ; under tail-coverts very ample. Two species, 

 distiuijuislicd by shape of tail from those of tlie preceding or following genus. The extralimital 

 one is /'. it'tlii/s of the Grdajxipos. 



V. polafi'ica. (Gr. irtXayiKik, prhif/i/cos, oceanic.) Co.MMON Stormy Petrel. Above, 

 glossy browniisli-black, bclnw uidH' fuliginous; upper tail-coverts white, with black tips; 

 white streaking on crissum. ami usually white touches under the wings. Bill and feet black ; 

 no yellow on webs. Leuirtii 5..")0-5.75 ; wing 4.50-4.75; tail 2..50; bill 0.45; gape 0.62; 

 tarsus 0.90; middle toe and claw 0.82, outer 0.88, inner 0.65. Egg 1.09 X 0.85. Nestlings 



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