NATURAL SCIENCES OF PHILADELPHIA. 187 



even invading the throat. In immaturfi individunls, also, the lateral inferior 

 caudal tec'riees may be more extensively hued witVi plumbeous blaek. They 

 are never, however, so much darkened as is usual in obscunts or ojiialhomela^. 



This species may be always recognized among its congeners by the follow- 

 ing combination of characters: its peculiar dimensions (see above), joined 

 to the very dark upper parts, this color descending far on the sides of the 

 head and breast, leaving a conspicuously white under eyelid; the almost en- 

 tirely white under tail coverts and the comparative shortness and character- 

 istic degree of roundness of the tail. 



This is so very distinct, and at the same time so well known a species, that 

 it hardly requires comparison with any other. The features in which the P. 

 yelcuanu.i ditiers from it will be pointed out under the head of the latter. 



PuFFiNus Yelcdanus, Bp. cx Acerb. 



FroceUaria Tjelkouan,* Acerhi, " Bibliot. Ital., 1S27, cxL, Agost. p. 294;" 



et "Bull, des Sciences Nat., 1S29, xvi. p. 463. Schlegel, Monog. Proc. 



Mus. Pays-Bas, 1863, p. 29. Puffimis yelkouan, Bonaparte, Comptes 



Rend. Tab. Longip. , Id". Consp. Av. ii. 1856, p. 205. 



Hahi/at. — More eastern portions of the Mediterranean Sea ; especially in the 



Black Sea, and in the vicinity of the Bosphorus. 



With this species, admitted by the majority of modern authors, I am ac- 

 quainted only through descriptions. This is specially to be regretted, since 

 authors are at variance regarding its characters and affinities, and are not even 

 entirely agreed upon its specific validity. Bonaparte considers it to be the 

 representative of olscurus in the Black Sea and vicinity, and says that it is 

 smaller than that species (being only 10 inches in length) and has a slenderer 

 bill. Dr. Schlegel, on the contrary, considers it as most intimately allied to 

 anglorum, which it replaces in that locality. As far as I can judge from a 

 careful study of published desciiptions, I entirely agree with Dr. Schlegel in 

 opinion. On comparing it with anglorum, Dr. Schlegel has found it to diflt'er 

 as follows : In the greater elongation of the point of the wing ; in the color of 

 the upper parts being lighter and rather tending to grey than black, as is 

 also the color of the dark feathers of the crissum ; and in the unif.^rm deep 

 gray of the lateral under tail coverts, these latter being, in anrjloruni, blaek 

 on their outer, and white on their inner webs. 



The following detailed mea,surements are given by the same author, taken 

 from individuals coming from the Bosphorus, near Constantinople. They are 

 to be compared with those of angJorum, already given on a previous page. 

 Wing (from the carpus), 8-33 to S-66 inches and hundredths. Tail, 2*40 to 

 2-60. Bill along culmen, 1-20 to 1-50 ; height, -28 to -33 ; width, -40. Nasal 

 tubes, -16 to -20. Tarsus, 1-66 to 1-80 ; middle toe, 1-58. 



PiTFFiis'us OBscuRus, Vieill. ex Gmel. 



FroceUaria obsciira, Grmel., Syst. Nat., i. jxars ii. 1788, p. 559. Lath., 

 Ind. Ornith., ii. 1790, p. 828, et auct. antiq. Vieillot, Nouv. Diet. H. 

 N. 1817, XXV. p. 423. Puffinus ohscurus, Bonap., Synop., 1828, p. 371. 

 Vieillot, Gal. Ois., 1834,' ii. p 230 , pi. 292. Audub., Bds. Amer., 

 1844, vii. p. 216, pi. 458. et al, auct. recent. Nectrls ohscura, Kuhl, 

 Beitriige ZooL, 1820, p. 147, pi. xi. fig. 11. Cymotomus ohscurns, Mac- 

 gillivray, Man. Orn., 1844, ii. p. 13. "Puffinus Pberminier/, Lesson," 

 fide Bp. Puffinus fioridanus, Musfei Beroliensis," fide Bp. 

 HnJ})tat. — The warmer portions of the Atlantic Ocean, especially the Gulf of 

 Mexico, and the coasts of the Southern United States ; abundant in the Ba- 

 hamas and Bermudas. Wanders as far north as New Jersey, and is accident- 

 ally found in Europe. Apparently replaced in the corresponding latitudes of 

 the Pacific Ocean by my Puffinus opisthomehis. 

 For so long known a species, the present has remarkably few synonyms, 



* I find this barbarous name Tariously spelled yelkouan, yelkuan, yelkoan, eic. I bun. seea 

 fit to moflify it insomuch that it may jjicsent somcwJiat of a classical aspect. 



1864.] 



