STERCOEARIUS BUFFONI, LONG-TAILED JAEGER. 617 



" cepphus " really refer. This difficulty results partly from the brevity aiid vague char- 

 acter of the diagnoses given, and partly from the fact that the two species were really 

 confounded (except by Brisson) until a comparatively recent date. From this it re- 

 sults that many of the older names and citations may without difficulty be refuired to 

 either species. This has been done ; some authors considering Briinnich's or Liunteus' 

 "parasiticwa " to refer to the Long-tailed, and others thinking that it was based upon 

 the common species, until the identification of this name has become almost a matter 

 of choice, or rather of tacit understanding. A glance at the synonyms of the two spe- 

 cies will show that authors are about equally divided on this point. Before the intro- 

 duction of " richardsoni" by Swaiuson, the Common Jager usually received the appel- 

 lation of parasiticus, but after the adoption of Swainson's name for this species by 

 Temminck and others, the name parasiticus was for some years almost universally 

 applied to the Long-tailed Jager. Within the last few years, however, the name has 

 again reverted to the common species, and Buffou's Jiiger has usually been called 

 "cepphus." This identification of Briinnich's name is sanctioned by Gray, Bonaparte, 

 and other writers. The following are my reasons for rather referring it to the young 

 poniarinus : 



It is apparent, from almost every sentence of Briinnich's description of eepplms, that 

 he had in view a young bird of the year, in the state in which it is transversely waved 

 with rufous and dusky, &c. The only point to determine is, what species it is the 

 young of Regarding its size, Briinuich compares it with his Catkaracta slcua, saying 

 that it is much smaller than that species, and the size oi parasitita. The young-of-the- 

 year of pomatorhinus is more nearly the size of the adult parasiticus than is the young of 

 the Long-tailed Jiiger. The account of the colors, proportions, &c., which follows, 

 agrees precisely with those of the joang 2iomatorhinua ; and when we remember that at 

 that time the differences between the Common and Bnffon's Jiiger were not appreciated, 

 it seems by no means certain that Brlinnich had the latter in view in drawing up his 

 description. He would in that case have doubtless compared it with the paramticiis. 

 Moreover, authors who wrote but shortly after Briinnich's time, considered his cepphus 

 to be the pomatorhimus ; thus, e. g., Latham places it as a synonym of that species. I by 

 no means insist upon its reference to pomatorhimus, but merely wish to show that it very 

 possibly belongs there, and that it is altogether too indefinite to be employed in either 

 connection. 



The name longicaudatm of Brisson (1760) is the very first one accompanied by a suf- 

 ficiently definite description to enable the species to be identified. As Brisson is no au- 

 thority for species, the name huffoni, proposed by Boie, is the fii'st tenable specific 

 designation. 



I have already given my reasons for referring the Larus parasiticus, Latham, to this 

 species, rather than to the parasiticus of Brlinnich. 



The Lestris lessoni of Degland (1838) is, according to that author's own admission, 

 based upon the youg iuffoni. This same immature plumage of this species has served 

 as the basis of Lestris crepidata of Brehm (1823). 



Subfamily Labin^. 



DiAG. Laridae rostro Integra, maxillce supericris apice aduncd, inferiorem excedente. 



Ch. Bill entire ; the apex of the upper mandible overhanging the tip of the lower. 

 General shape of the bill as in Lestridinos. Eminentia symphysis always prominent. 

 Rami of inferior mandible divaricating at an acute angle. Submental space partially 

 feathered. Feathers of forehead extending further on the sides than on the oulmen of 

 upper mandible. Nostrils direct, linear-oval, somewhat club-shaped, pervious, situated 

 on the side of the upper mandible near its base. Wings long, strong, and acutely 

 pointed, the first primary usually longest. Tail usually square, or very slightly emar- 

 giuate ; sometimes forked ; in Bhodostethia cuneate. Legs ambulatorial, of moderate 

 length, jjlaced far forward. Tibiae denuded for a greater or less space below ; moder- 

 ately stout, anteriorly scutellate, posteriorly smoothly reticulate. Toes as in the other 

 subfamilies. Webs moderately full, always more or less emarginate. Hind toe always 

 fully developed, except in Bissa. Of very variable size, from the largest of the family 

 to nearly the smallest. Plumage full and thick, especially beneath ; varying in color 

 greatly with age and season, hardly, if at all, with sex. Sexes of nearly ecjual size, 

 female usually a little the largest. 



Anatomical characters. — For these see the account of the anatomy of L. argentatus 

 (smithsonianus), a typical species well illustrating the internal structure of the whole 

 subfamily. 



The numerous species of this cosmopolitan group have been unwarrantably subdi- 

 vided into a large number of genera, so-culled by modern systematists. It may uot be 

 possible, even were it judged expedient, to define these genera as such ; for with the 

 exception of the cuneate-tailed lihodostolhia, and the fork-tailed A'ama, no characters 

 are observed beyond those of pattern of coloration, by which the groups can be trench- 



