STERNA LUNATA, PEALE'S TERN. 703 



These two are the same bird, and I presume them to be the "infvscata, Licht.," of 

 Gray's Hand-list, though I have no means of satisfying myself that such is the case. 

 These birds run extremely close to the subject of the present article (my former dis- 

 color) — too close to be specifically separated, though a geographical variety is indicated. 

 The bill is much slenderer, only 0,30 high at the base. The frontal lunula reaches but 

 little beyond the eyes, instead of nearly half an inch behind them ; the loral blacls 

 stripe is narrower. The black cap is separated from the smoky-gray bacli by a very 

 narrow, sharp, cervical collar, instead of a more gradual change. Only the outer t.ail 

 feather is mostly white, instead of the two outer. The size of equally adult specimens 

 is noticeably less — wing about 9.75 instead of 10.50. Now there is no reasonable doubt 

 that Gray's Nos. 11080 and 11083 are one and the same bird ; i. e., that there is but one 

 of these "sooty" Terns heside fiUiginosa ; Blasius has already said so, and I entirely 

 agree with him. The question is as to the distribution of the synonymy between the 

 two varieties. Gmelin's and Latham's names, panayensis and pancya {hoth= anaatheia, 

 Scop., I. c), apply as well to one as to the other. As to nuhilosa, Sparmm., Gray has it 

 under ivfuscata, while Blasius assigns it far elsewhere — to cantiaca; the name is thus 

 obviously too uncertain to be used. 



Blasius recognizes but three species of Haliplana ; lunata, Peale, panayensis and fu- 

 liginosa ; and such is empliatically my own decision. To the latter, fuliginosa, he 

 assigns as synonyms infuscata, Licht., and melanoptera, Sw., besides the well-known 

 serrata and guttata of Forster, throwing upon panayenda all the rest of the synonymy, 

 namely, fuliginosa and fuligula, Licht. ; infuscata, Eupp. ; antarctica, Cuv. ; oahuensis, 

 Blox. ; and discolor, Cones. It is probably not possible to locate all these names satis- 

 factorily, nor to reconcile the conflicting views respecting them. 



To complete an account of this group of dark-colored Terns with white frontal lu- 

 nula and white under parts, and black bill and feet, I append a notice of iS. lunata, 

 Peale.* 



Genus HYDROCHELIDOlsr, Boie. 



X Ballus, sp., Linn., Syst. Nat. i, 1758 (ed. x), 153. 

 < Sterna, Linn., Syst. Nat. 



= Hydrockelidon, Boie, Isis, 1822, 563. (Type S. nigra, Linn.) 

 = Firalva, Leach, Gen. Zool. xiii, 1826, 166. (Same type.; 



= Pelodes, Kaup, Sk. Ent. Eur. Thierw. 1829, p. 107. (Type S. leucopareia, Natterer ; 

 =liyl)nda, Pall.) 



Gen. ch. Bill a little shorter than the head, longer than the middle toe and claw ; 

 very delicate, slender, acute; culmen and commissure decidedly declinato-convex, the 

 amount of curvature increasing toward the tip ; outline of rami and gonys both eon- 

 cave, the former most so ; eminentia symphysis prominent and very acute. Wings 

 exceedingly long, pointed, of same color as baf.k, without distinct m-arkings on either 

 web. Primaries broad and not very tapering, not acute ; the terti.ils very short, 

 rounded, not slender nor flowing, reaching in tlie folded wing only half way to the tip 

 of the longest primary. Tail ratlter short, contained 2| times in the wings, only moder- 

 ately emarginate (much as in GelocJielidon), the lateral feathers but little exceeding the 

 next, not tapering and acuminate; all the feathers broad and rounded. Feet-slender 

 and short ; tarsi much abbreviated, rather less than the middle toe alone. Toes mod- 

 erately long ; the webs rather narrow, and very deeply incised. Size small, general form 

 delicate ; colors mostly Hack, the tcings and tail plumbeous, in type of the genus. 



The group of Terns, of which S, larifomiis of Linnjeus may be taken as the type, forms 

 a natural assemblage very closely allied to Sterna^ proper, but differing in certain 



* Sterna lunata, Peale, U. S. Expl. Exped. 1846, No. 725; Cass., Hid. 1858, No. 716; 

 PiNSCH & Hartl., Fn. Central Pol. pi. 18, f. 3. — Sydrochelidon (Haliplana) lanata, 

 Gray, Hand-list, No. IW81.— Haliplana lunata, Blas., J. f. O. 1866, 80. (Description 

 froin the type of the species. No. 15744, Paumotn Islands (Vinceunes), Se£it. 1839.) Bill 

 and feet black. Cap black, with a long, narrow, white frontal lunule, whose horns 

 reach behind the eyes, cutting off a black stripe through the eye to the base of the bill 

 at the nasal fossa, tfpper parts uniform dark grayish plumbeous (not smoky gray), 

 the color extending on the wing-coverts and tail. Cubital edge of fore-arm rather 

 darker than other upper parts. Quills fuscous, silvered with the color of the mantle, 

 their inner webs with the usual white stripe, which, however, does not nearly reach 

 their ends. Ou the longer primaries, where this stripe is sharpest, it is bordered inter- 

 nally with a narrow prolongation of the fascous along the margin of the inner web. 

 Outer tail feather white tor all that portion which is overlaid by the next feather, its 

 • outer web white to the tip ; next tail feather with considerable white basally on the 

 inner webs. Entire under parts pure white. Length may have been about 13 inches; 

 wing, 10.25 ; tail about 6, forked full half its length ; bill along culmen, 1.60 ; tarsus, 

 0.75; middle toe and claw, rather over 1. This species is the obvious link between 

 "Haliplana" and Sterna proper. 



