AVES. 389 



Sp. Phaeton cethereus L., Buff. PI. enl. 998, Less. Ornith. PI. 114, fig. i ; 

 — Phaeton phosniciirus Gm., Buff. PL enl. 979, Gder. Iconogr., Ois. PI. 

 65, fig. 3 ; — Phaeton jlavirostris Beandt, Lepturus candidus Bkiss. Ornith. 

 VI. Tab. 42, fig. 2, Bdff. PI. enl. 369. Compare J. F. Brandt Tentamen 

 monographice generis Phaeton, Mem. de VAcad. imper. des Sc. de St. Peters- 

 hourg, 6ifeme S^rie, Sc. math, et phys. Tome v. 2, 1839. (These birds recall 

 Sterna and Larus, but must, nevertheless, be referred to the family of the 

 Steganopods.) 



Family IV. Longipennes. Bill with margins entire. Wings 

 elongate. Feet stilted, with tibiae seminude, in some tetradac- 

 tylous, witli hallux free, posterior, simple, in some tridactylous, 

 with hallux none. 



A. Nostrils Imear, placed at the base of bill, pervious. 



Bhjnckojys L. Bill long, compressed, straight; lower mandible 

 two-edged towards the tip, longer than upper, with tip truncate. 

 Feet tetradactylous, with palmar membrane excised. Wings very 

 long; first two quills longer than the rest. 



Sp. Rhynchops nigra L., Buff. PI. enl. 357; Lesson Ornith. PI. 113, fig. i, 

 from America ; another species occurs in the eastern hemisphere, Rhynchops 

 jlavirostris Vieill., Rh. orientalis Ruepp. Atlas PI. 24. The lower man- 

 dible with its sharp upper edge is received in a groove of the upper man- 

 dible like the blade of a pocket-knife in its handle. 



Sterna L. Bill long, straight, compressed, pointed, with man- 

 dibles subequal, the lower shorter. Feet small, tetradactylous, with 

 palmar membrane mostly excised; tarsi scutellate anteriorly. Wings 

 very long, with first quill-feather longer than the rest. 



a) Tail cuneate, longer. Palmar membrane scarcely excised, large. 



(Sub-genus Anous Leach, Gray, Megalopterus Boie.) 



Sp. Sterna stolida L., Buff. PI. enl. 997, the Noddy ; on the Atlantic Ocean 

 between the tropics, Indian Ocean and South Pacific, &c. 



b) Tail forlced, or emarginate. Palmar memhrane deeply excised hetiveen 

 the toes. 



Sub-genus Sterna. (Sterna Gray, with addition of sub-genera Uydro- 

 chelidmi Boie, Gray, Phcetusa and Gygis Wagl. and Gray.) 



Sp. Sterna hirundo L., Buff. PI. enl. 987, Lesson Ornith. PI. 113, fig. 2, 

 the sea-swalloiv; bill and legs red, head on the top as far as the eyes black, 

 body light-grey above, white below; the same colours in Sterna minuta L., 

 Buff. PI. enl. 998, Naumann, Taf. 254, which, however, is much smaller, 

 and in addition is distinguished by white above the eyes. Similarly 



