450 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Vog., ii, 1891, 206.— Sharpe, Review Rec. Att. Classif. Birds, 1891, 72 

 Hand-list, 1899, xiv, 138. — Saunders, Cat. Birds, Brit. Mus., xxv, 1896, 

 xiii, 4, 152. — Beddard, Struct, and Classif. Bii'ds, 1898, 356. — Salvin and 

 GoDMAN,. Biol. Centr.-Am., Aves, iii, 1903, 416. — Knowlton, Birds of the 

 World, 1909, 393. 



^Rhynchopidae Ridgway, Proc. U. S. Nat. Mus., vi, April 11, 1883, 409. — 

 Baird, Brewer, and Ridgway, Water Birds N. Am., ii, 1884, 191. 



=Rhynchopsidx Ridgway, Proc. U. S. Nat. Mus., iii, Sept. 4, 1880, 240. 



—Rynchopidx American Ornithologists' Union, Check List, 1886, 96; 3rd ed., 

 1910, 48.— Oberholser, Outl. Classif. N. Am. Birds, 1905, 3. 



Very long-winged, small-footed Lari with bill wholly unique, the 

 mandible much longer than the maxilla, both compressed to knife-like 

 thinness (except at extreme base), the distal portion of the maxilla 

 grooved beneath to receive the very sharp tomia of the distal portion 

 of the mandible, the latter much higher at tip than the latter and 

 obliquely truncate or subtruncate in lateral profile. Wing very long, 

 pointed, the longest primary exceeding distal secondaries by about 

 two-thirds length of wing. Ambiens muscle and biceps slip absent 

 (present in other Lari) ; tendons to ulna §ide of arm, 2 (1 or none in 

 other Lari). 



The RynchopidjE are perhaps most nearly allied to the Sternidse 

 but differ — not only from the latter but from all other birds — in the 

 altogether peculiar conformation of the bill. They also differ from 

 other Lari in absence of the ambiens muscle and biceps slip, and in 

 possessing two tendons to the ulna side of the arm. 



In general habits the Rynchopidfe are much like the Sternidse 

 and Laridae, but their manner of feeding is wholly different, for in 

 search of their food the mouth is opened and the long, knife-like 

 mandible buried in the water as the bird skims along its surface. 



Only one genus is ktiown, this being represented by about four 

 species, of which two are American, the others inhabiting the seas 

 and estuaries of Africa and India, respectively. 



Genus RYNCHOPS Linnaeus. 



Rynrhops Linn^us, Syst. Nat., ed. 10, i, 1758, 138; ed. 12, i, 1766, 228. (Type 



by monotypy, Rynchnps nigra Linnseua.) 

 Rhynchops (emendation) Latham, Index Orn., ii, 1790, 802. 

 Rkijncops (emendation) Temminck, (^at. Syst., 1807, 181. 

 Rhincops (emendation) Bonaparte, Ann. Lye. Nat. Hist. N. Y., ii, 1828, 19. 



351, 447. 

 Rhyncops (emendation) Vieillot, Nouv. Diet. d'Hist. Nat., iii, 1816, 338. 

 Rygchopsalia Brisson, Orn., vi, 1760, 222 (ex Barr^re, Orn. Sp. Nov., 1745. 20"). 



(Type, '^ Rygchopsalia" = Rynchops nigra Linnaeus.) 

 Rhynchopsalia (emendation) Gloger, Hand-u. Hilfsb., 1842, 463. 

 rsalidorhamphos « Dumont, Diet. Sci.^at., iv, 1805, 173. (Substitute name for 



Rynchops Linnreus.) 



o "^aXU (4'a\t5os), a pair of shears, a kind of razor; pd/u^os, beak. (Richmond.) 



