134 PROCEEDINGS OF THE ACADEMY OF 



brown, more or less conspicuously tipped with whitish. The tail feathers are 

 like the outer primaries. The bill is deep blackish horn. The outside of the 

 tibia? and the exterior toe are brownish ; the rest of the feet including the 

 webs yellowish flesh color. 



Dimensions. Total length 18.00 to 20.00 inches and hundredths; expanse 

 of wings 43.00 to 45.00. Bill along culmen 2.00 ; from feathers on side of 

 lower mandible to tip 1.75; depth at base .65, width . GO ; wing from the 

 carpus 13. U0; tail : central feathers 5.75; exterior do. 4.75 ; difference 1.00 ; 

 tarsus 2.40 ; middle toe and claw 2.90 ; outer do. 2.75 ; inner do. 2.30. 



Variations. The differences in dimensions which this large species presents 

 are so great that the above measurements can only be considered as an aver- 

 age ; and individuals will be found considerably above and below the standard. 

 The bills of various specimens, as well as the tarsus and toes, differ to the 

 amount of two or even three tenths of an inch ; the wings from the carpus 

 three-fourths of an inch, or more, and the tail proportionally. The relative pro- 

 portions, however, and the shape of these several parts appear to be pretty 

 constant. 



There also exist greater variations in color than are found in most of the 

 species. The difference appears to depend chiefly upon age, or rather upon the 

 age of the feathers themselves. Just after the moult, when the feathers are 

 fresh and new, they are of a clear deep brown with a considerable of a plum- 

 beous tinge, and their margins are exceedingly light colored, in fact almost 

 white on the tertiaries, etc. With advancing age the feathers become more 

 and more of a duller brown, much like that given by Audubon in his plate ; 

 the margins are broader, less deeply defined, and simply of a dull grayish 

 brown. Constant characters, however, seem to be the uniformity in color of 

 the feathers of the head, there being no light margins to them ; the peculiar 

 line of demarcation on the sides of the head and neck, and the partially white 

 upper, and almost wholly dark under tail coverts. Audubon's plate of this 

 species, otherwise excellent, is very wrongly colored as regards the bill and 

 feet. The bright tints he gives them rather appertain to another species. 



Notwithstanding these variations, the present species is so marked a one 

 that it is not readily to be confounded with any other. Some small and light 

 colored specimens look something like examples of P. Kuhlii ; the exact dif- 

 ferences between the two will be given under the head of the latter. From 

 P. angiorum, its size and the color of the upper parts at once distinguish it. 

 P. obscurus and its allies are too different to require comparison. P. major 

 may always be recognized by the peculiar size and shape of the bill (care- 

 fully examine preceding description) ; by the lighter margins of the feathers 

 of the upper parts ; by the line of demarcation of the white and brown on 

 the sides of the head, as above given ; and by the colors of the under tail 

 coverts and flanks, which are the reverse of those of Kuhlii, its nearest ally. 

 However light the color of the upper parts may be, they never acquire the 

 real ashy tint which is a distinguishing characteristic of the latter species ; 

 and the colors of the bill and feet are always conspicuously different. 



This species has an exceedingly extensive range. It apparently inhabits 

 the entire Atlantic Ocean, up to exceedingly high latitudes. Dr. Schlegel 

 has specimens from points on the west coast of Africa and from the Cape of 

 of Good Hope. A specimen before me from Terra del Fuego, collected by Mr. 

 T. R. Peale, Naturalist of the U. S. Exploring Expedition, is identical with 

 the common north Atlantic biid. 



Puffin us angloeum, Temm. ex Ray. 



Procellaria angiorum, Raii Syn. 1713, p. 134, sp. 4. Temminck, Man. 

 Urn. ii. 1820, p. 805. Schlegel, ftlus. Fays-Bas, 1863, p. 28. Paf- 

 Jinus angiorum, Brisson, Oinith., 1760, vi. p. 131. Temminck, Man. 

 Ornith. iv. 1840, p. 509. Bp. Gmsp. av . 1856, ii. p. 203. Law- 

 rence, Gen. Rep. Bds. N. Auier., 185;?, p. 834 ; et auct. recent, fere 



[April, 



