BIRDS OF NORTH AND MIDDLE AMERICA. 485 
Genus STERNA Linnezeus. 
Sterna Linnagus, Syst. Nat., ed. 10, i, 1758, 137; ed. 12, i, 1766, 227. (Type, aa 
designated by Gray, 1840, Sterna hirundo Linneeus.) 
Onychoprion Wacutr, Isis, xxv, 1832, 277. (Type, by monotypy, Sterna serrata 
Wagler =. fuscata Linneus.) 
Chelido® Brtupere, Synop, Faunae Scand., i, pars 2, 1828, tab. Aand p.193. (New 
name for Sterna Linnzeus.) 
Planetis Wacuxr, Isis, xxv, 1832, 1222. (Type, Sterna guttata Wagler ex Forster, 
manuscript, =S. fuscata Linnzus.) 
Planetes (emendation) Gistex, Naturg. Thierreichs fiir héhere Schulen, 1848, p. x. 
Haliplana Waauer, Isis, xxv, 1832, 1224. (Type, Sterna fuliginosa Gmelin= 
S. fuscata Linnzeus.) 
Melanosternab Buyru, Journ. Asiat. Soc. Bengal, xv, 1846, 373. (Type, Sterna 
anzthetus Scopoli.) 
Thalassipora ‘‘Boie” Riprrtn, Syst. Ueb. Vog. Nord-ost-Afrika, 1845, 140. 
(Type. Sterna infuscaia Lichtenstein—=S. fuscata Linnzus). 
Dipsaleon Giste., Naturg. des Thierreichs fiir hdhere Schulen, 1848, p. x. (New 
name for Planetis Wagler.) 
Medium-sized to rather small Sternide (wing about 210-300 mm.) 
with tail more than half as long as wing, deeply forked and with 
lateral rectrices attenuated (sometimes subacuminate) terminally, 
and occipital feathers normal (short and blended). 
Bill about as long as head, moderately slender, its greatest depth 
nearly equal to half the distance from anterior end of nostril to tip of 
maxilla, the more or less prominent gonydeal angle usually about 
midway between tip of mandible and malar antia, rarely anterior to 
the middle, more often decidedly posterior to the middle; nostril 
narrowly oval, elliptical, or linear, always separated from the latero- 
frontal antia, but width of intervening space variable. Wing long 
and pointed, the longest primary (outermost) exceeding distal 
secondaries by at least twice the distance from tips of the latter to 
bend of wing (except in 8. melanogastra). Tail much more than half as 
long as wing, forked for more than half its length (except in S. melanau- 
chen) ,° the lateral retrices more or less slender and attenuated (some- 
times sub-acuminate) terminally. ‘Tarsus sometimes longer, some- 
times shorter, than middle toe without claw; webs with anterior 
margins moderately excised. 
Plumage and coloration.—Occipital feathers normal (short and 
blended), except in S. melanauchen.© Adults with at least part of 
pileum and nape uniform black (except in S. trudeaut) sometimes with 
a white frontal crescent, one species (S. melanauchen)¢ with only the 
nape and a stripe through the eye black; rest of upper parts plain 
gray (more or less deep) to sooty black; under parts white or gray, 
a‘s |, graecum Xedrdw, Hirundo marina, conservavimus.’’ (Billberg.) 
b Médas (meAap-), black; +Sterna. (Richmond.) 
¢§, melanauchen should probably be separated generically. 
