88 PROCEEDINGS OP THE ACADEMY OP 



it in the length, straightness and attenuation of the bill ; and in the very unusu- 

 ally long toes, with their broad, full, interdigital membranes. The pattern of 

 coloration is very dissimilar from that of most of the species of Fregetta or 

 indeed of any other genus of Procellarieae. 



The long and well known Procellaria fregetta of Linnaeus is its typical and 

 only species. 



I. Pel^godroma fregata, Bp. ex Linn.* 



The history of the synonymy of this species is somewhat involved, since, as 

 demonstrated in the annexed foot-note, the Procellaria fregata of Linnteus has 

 been very variously interpreted by different writers. Some authors have con- 

 sidered it as referring to the tropica of Gould, others to the grallaria of Yieillot, 

 others again to the melanogastra of Gould ; while one author has applied the 

 name to a new species, afterwards dedicated to him by Bonaparte. (Fregetta 

 Lawrencii.) But I entirely agree with Prof. Lichenstein," (foot-note on page 180 

 of Forster's " Descriptions Animalium") and with Bonaparte (Conspectus, p. 

 198) that the Froc. fregata, Linn., was based upon the bird first described by 

 Barrere, and which Latham subsequently more definitely characterized as 

 Procellaria marina. With this view of the case, the following is an exposition 

 of the synonymy of the species in question : 



Proc. fregata Linnasus, S. N. i. 1766, (nee Forster, nee Kuhl., nee Lawrence.) 

 Procellaria marina, Latham, Ind. Ornith. ii. 1790, et Kuhl, Monog. Proc. 1823, 

 p. 138, pi. x, fig. 2. Thalassidroma marina, Gray, Genera Birds, iii. 1849. Pe- 

 lagodroma marina, Reichenbach, Syst. Av. Pelagodroma fregata, Bp.,Consp. Av. 

 n. 1856, p. 198. Procellaria sequorea, Solander. Procellaria hypoleuca, Webb et 

 Berth., Av. Canar. 



This large and beautiful species, so peculiar both in form and colors, is too 

 well known to require any description in this connection. 



There is in the Philadelphia Academy a very young individual of this species 

 which has not yet wholly emerged from the downy state of plumage. Yet, 

 although so very immature, the peculiar color and markings of the adults are 

 already entirely apparent. This is ample evidence that the birds of this group 

 are subject to no changes of plumage of any consequence in their progress 

 towards maturity. I have fortunately been able to extend the same observa- 

 tion to other species. A fledgling of Cgmochorea leucorrhoa, now before me, has 

 exactly the pattern of coloration of the adults, and the uropygial white is 

 already discernable, the only difference being that the black is rather of a 

 slaty than of a fuliginous tint. The chief variations of plumage to which, at 

 least, the fuliginous species are subject, will all be found, I think, to depend 

 upon season. After the moults, when the feathers are fresh and new, they are 

 much darker, and more uniformly so, than after they have become old and 

 worn. Their tips then assume a somewhat lighter brown color, and the dull 

 brown alar fascia, common to so many of the species, becomes much more con- 

 spicuous. This is readily demonstrable by examining any of the fuliginous 

 species during the moult, when the old and new feathers will be found to be 

 quite different in the precise shade of the fuliginous brown. 



The preceding pages contain notices of all the known species of Procellarieae 



* Among the Procellarieae no name has been so indiscriminately used by authors for so many 

 different species as "fregata, Linn.," variously spelled fregata, f regatta, fregetta, etc. That this 

 may occur less frequently in future, and for convenience of reference, the following synoptical view 

 of the various applications of the word is given: 



Proc. fregata, Linn.=P. sequorea, Soland.=P. hypoleuca, Webb, et Berth.=P. marina, Lath.=> 

 Thai, marina, Uray. =l\lagodroma marina, Reich.=Pelagdroma fregata, Bp. ex L., of this 

 paper. 



Proc. fregata, Forster.=P. grallaria Licht. nee Vieill.=(probably) Thai, melanogastra, Gold,= 

 Fregetta melanogastra, Bp. ex Gould, of this paper. 



Proc. feegatta, KwM.=P. gratta rin, \ici\\.=Thal. oceanica, Bon. (li2S).= Thal.lcucogastra, 

 Qoul&.=Fregetta gralb ria, Bp. ex Vieill., of this paper. 



Thai, fregetta, Lawr. Fregetta Lawrencii, Bp. ex Lawr., of this paper. 



[March, 



