NATURAL SCIENCES OF PHILADELPHIA. 145 



Procellaria (sEstrelata) rostrata, G. R. Gray, Cat. Bds. Pacif. Isl. 1859, p. 56. 



Habitat. Tahiti. (Peale.) 



The following detailed description of this little known and hardly recognized 

 species is taken from Mr. Peale's type specimen, now before me. 



Form. The bill is much shorter than the head or tarsus, about two-thirds 

 the middle toe without its claw ; exceedingly robust, especially at the base 

 where it is as high as broad, and where its height is nearly equal to half the 

 length of the culmeu. The lateral lamina? of the upper mandible are very 

 wide and large ; especially basally, where their upper margins rise so high as 

 to be nearly on a level with the dorsum of the nasal case, the tubes being 

 thus almost buried between the lamiuse. In consequence of this shape of the 

 lateral laminae the sulcus is extremely sinuate, extending from the top of the 

 root of the nasal case to the commissural edge of the unguis, near its middle. 

 The inferior edge of the laminae, forming in great part the cutting edge of the 

 upper mandible, is decidedly convex in outline. The unguis is large and 

 strong, and its elevation, which begins almost directly from the termination 

 of the nasal case, as well as its convexity and decurvation, are very great. 

 The under mandible is straight, its sulcus strongly pronounced, its tip de- 

 curved and acute, its unguis large, its gonys quite concave, though there is 

 but a slight protuberance at the symphysis. 



The nasal tube is short, wide, depres ed, turgid, not carinated, convex in- 

 outline both antero-posteriorly and transversely ; its apex obliquely truncated, 

 broad, depressed, not emarginated, the nares circular, separated from each 

 other by a rather thick septum which comes forward to the very end of the 

 nasal case. The frontal feathers encroach far upon the dorsum of the tubes, 

 with a rounded termination, and then slope gradually backwards and down- 

 wards.* The feathers on the sides of the lower mandible do not extend to a 

 point perpendicularly below the apex of the frontal feathers. 



The wings are long, the first primary considerably surpassing the second ; 

 and when folded they reach considerably beyond the end of the tail. The 

 latter is of moderate length, contained rather more than twice in the length 

 of the wing from the carpus ; and it is much graduated in shape. 



The feet are comparatively large for the size of the bird, absolutely about 

 equalling those of Lessoni, which is a larger bird. The relative proportions 

 of the tarsus and toes are much the same as in other species. The hallux is 

 rather long, slender and acute. 



Dimensions. Length about 14 inches, "extent 39 - 50," (Peale.) Wing 11 ; 

 tail 4-75 ; bill along chord of culmen l - 37 ; heighth or width at base '66 ; nasal 

 tubes "25 ; from feathers on side of lower mandible to its tip 1-20. Tarsus 

 1*75 ; middle toe and claw 2 - 25, outer do. 2 - 12 ; inner do. 1*80; hallux '25. 

 From apex of longest secondary to tip of longest primary in the closed wing 

 3-25. 



Color. Entire upper parts pure deep blackish brown, including the under 

 surfaces of the wings and tail feathers ; everywhere of a nearly uniform tint ; 

 but a little darkest on the outer webs and tips of the primaries, and somewhat 

 lighter on their inner webs, especially towards their bases. This color of the 

 upper parts extends around the sides of the head, neck and breast ; but be- 

 comes on the chin, throat and breast a little paler; and includes the sides 

 under the wings, and crissum. Kest of under parts, including the under tail 

 coverts, pure white ; the latter however have a few isolated brownish streaks. 

 The line of demarcation between the dark and light colors on the breast is not 

 very trenchant. The bill is black. The tarsi are pale yellow ; probably flesh 

 colored in life. A small space on the lower part of their external aspect, and 

 the whole toes and webs (except a small yellow spot on the inner web near 

 its base) are black. 



This color of the upper parts is a pure very dark brown, with no mixture 



*Xnis outline of the feathers on the bill shows an approach to that seen in Pagodroma, and is 

 quite different fiom anything that obtains in the other species of the genus *Eslrelala. 



1866.] 10 



