144 



PROCEEDINGS OF THE ACADEMY OF 



into dull brownish gray on the edges of the inner webs of the primaries. 

 Some of the under wing coverts are edged and tipped with grayish white. A 

 few of the Ion? axillars are chiefly white with their terminal portions slaty. 



The preceding description is taken from a specimen from the South Indian 

 Ocean, mentioned by Mr. Cassin in the Proceedings, as above cited. The fol- 

 lowing is from one of the specimens taken by Mr. Peale, one of the natural- 

 ists of the United States Exploring Expedition under Ci>m. Wilkes. The 

 specimen in question is labelled in Mr. Cassin's hand-writing "P. Lesso?}ii 

 Garnot:" and while absolutely identical in form with the species as usually 

 known and recognized presents the following exceedingly different colors : 



Young. No. 15709, Smiths. Register. Terra del Fuego, T. R. Peale. 

 Entire upper parts dusky fuliginous brown ; the dorsal feathers usually 

 with somewhat light margins ; the color deepening on the wings and tail into 

 brownish black. Some of the secondaries, tertials and upper coverts have a 

 slight cinereous tinge. On the head and nape the brown is lighter than else- 

 where ; and a somewhat diluted shade of this color extends adown the throat, 

 thus completely enveloping the head : and occupies likewise the upper half 

 of the breast, quite across, as well as all the sides under the win us. On the 

 crissum, and especially on all the under tail coverts except immediately 

 around the anus, the color again deepens into brownish black. The rest ot 

 the under parts are white. The circumocular region is darker than the 

 adjacent parts. 



The foregoing is the most immature plumage known to me, and it will be 

 noticed that not only the colors themselves, but the pattern of coloration is 

 radically distinct from those of the adults. In some specimens is recogniz- 

 able a faint shade of a darker color on the tips of the feathers of the other- 

 wise white under parts ; whence I infer that in very young birds the whole 

 under parts may be brownish or grayish. 



Dimensions. Chord of culmen 1-50; width or height at base *60 ; nasal 

 tubes -25 ; from feathers on side of lower mandible to its tip 115 ; along 

 rictus 2 - 0~>. Tarsus 1'65 ; middle toe and claw 2 - 50 ; outer do. 2'40 ; inner 

 do. 2-10. Wing 11-50 to 12 00. Tail 5"00 to 5'50. Graduation of lateral 

 feathers rather more than an inch. 



Synonyma. Amoug the older authors, I only find one name alba, of 

 Gmeliu and Latham which seems at all referrible to this sp"cies. P. alba is 

 evidently an yEslrelata, of about the size of Lesioni, and the colors as 

 described apply tolerably well to a somewhat immature example of this spe- 

 cies. But there is nothing in the diagnoses of either of these authors which 

 absolutely restricts the name to the P. Lessoni ; and, therefore, in the uncer- 

 tainty, I would by no means supersede M. Garuot's appellation Lessoni, the 

 description of which is quite pertinent. I believe Mr. Cassin, in the Proceed- 

 ings of the Philadelphia Academy, as above, was the first to refer the bird to 

 its proper genus. 



The Procellaria leucocephala of Forster is certainly this species. His 

 description is in every respect pertinent to the adult bird. Although the 

 name had been used, in manuscript, as applied to Drawing No. 98, for many 

 years, it was not published until 1844, and, consequently is antedated by 

 Lessoni of Garnot, (ls26). Forster's editor, Dr. Lichtenstein, says, probably 

 correctly, that leucocephala Forst. is the alba Gin. ; but certainly incorrectly 

 that "vix nisi setate differre videtur a Proc. hcesitata Forst. ;" whereas hcesi- 

 tata Forst. is not even congeneric with leuc cephala. 



I am unable to discuss the synonyms variegata, Bonnserte, and vagahunda 

 Solander, which I quote on the authority of Bonaparte. 



iEsTRELATA eostrata (Peale) Gray. 



Procellaria rostrata, Peale, Zool. U. S. Expl. Exped. 1848, p. 296. Cassin, 



Ornith. U. S. Expl. Exped. 1858, p. 412. 

 Rhantistes rostrata, Bp t Counpt. Rend. 1856, xlii. p. 768. 



[May, 



