BIRDS OF NORTH AND MIDDLE AMERICA. 553 



KEY TO THE SPECIES AND SUBSPECIES OF MEGALOPTEKUS." 



a. Lores light gray to grayish white, like pileum; general coloration lighter. 



b. Islands of western Indian Ocean (Seychelles, Mauritius, Madagascar, etc.) — . 



Megalopterus tenuirostris tenuirostris (extralimital).^ 



hb. West coast of Australia Megalopterus tenuirostris melanops (extralimital). 



aa. Lores black or very dark brown, in strong and abrupt contrast with gray or white 

 pileum; general coloration darker. 

 b. Whole forehead (as well as crown, etc.) distinctly white or gray, sharply defined 

 against black of lores; lores black, much darker than cheeks. {Megalopterus 

 niinutus.) 

 c. Pileum wliite or grayish white, in rather abrupt contrast with deep gray of 

 hindneck; gray of tail much darker. 

 (/. Color of under parts, hindneck, and upper back slightly darker. (West 

 Indies, Gulf and Caribbean coasts of Mexico and Central America, etc.). 



Megalopterus minutus atlanticus (p. 554). 



(id. Color of under parts, hindneck, and uj)i)er back slightly lighter and grayer. 



(PhiUppiue Islands.) Megalopterus minutus worcesteri (extralimital). c 



a Specimens of Megalopterus are so few in American collections (■nith the exception of 

 M. melanogenys and M. diamesus) that I am unable to bring together a sufficient series 

 to show clearly the relationships of the several forms. Therefore, tliis " key " is a 

 provisional one only. Besides the forms here mentioned, Mr. Gregory Mathews, the 

 latest reviser of the group, in his Birds of Australia, recognizes the following sub- 

 species, but I have not seen specimens of any of them, nor of M. tenuirostris tenui- 

 rostris and M. diamesus: 



Megalopterus tenuirostris melanops. — Anoxis melanops Govl\6l, Proc. Zool. Soc. Lend., 

 1845 (pub. Peb., 184G), 103 (lloutman's Abrolhos, w. coast Australia); Birds Australia, 

 vii, 1848, pi. 35 and text; Handb. Birds Australia, ii, 1865, All .—Megalopterus tenui- 

 rostris melanops Mathews, Birds Australia, ii, pt. 4, Nov. 1, 1912, 414, 41G.—Stenia 

 tenuirostris {not oiTemmlnck) Schlegel, Mus. Pays-Bas, Sternae, 1863, 37 (Australia). — 

 Anous tenuirostris Saunders, Proc. Zool. Soc. Lond., 1876, 670, part (monogr.); Stone, 

 Proc. Ac. Nat. Sci. Phila., 1894, 117, part (West Australia; crit. ).—Micranous tenui- 

 rostris Saunders, Cat. Birds Brit. Mus, xxv, 1896, 144, part (West Australia). — 

 (?)^noMS atrofuscus Stone, Proc. Ac. Nat. Sci. Phila., 1894, 117 " (Mer de Monte- 

 video "). — {'!)A[nous] atrofusms Ridgway, Man. N. Am. Birds, 2d ed., 1S96, 48, part. 



Not having seen either form of this species I am unable to give their distinctive 

 characters. 



Megalopterus minutus marcusi — Micranous marcusi Brj^an, Occ. Papers Bernice 

 Pauahi Bishop Mus., ii, 1903, 101 (Marcus Island). — Megalopterus minutus marcusi 

 Mathews, Birds Australia, ii, pt. 4, Nov. 1, 1912, 423 (Marcus Island; Mariannes?). 



b Sterna tenuirostrisTemmiwck, PI. Col., 1823, pi. 202 and text (" Senegal "); Schlegel, 

 Mus. Pays-Bas, vi, no. 24 (Sternae), 1864, 37, part (Reunion; Mauritius). — Megalop- 

 terus tenuirostris Gray, List Gen. Birds, 1840, 79. — Hydrocecropis tenuirostris Boie, 

 Isis, 1844, 179. — Anous tenuirostris Reichenbach, Natatores, 1848, pi. 20, fig. 288; 

 Saunders, Proc. Zool. Soc. Lond., 1876, 670, part, pi. 61, fig. 1 (monogr.); Hartlaub, 

 Fauna Madagasc, 1861, 86; Vog. Madagasc, 1877, 392; Milne-Edwards and Grandidier, 

 Nat. Hist. Madagasc, Ois., 1882, pis. 290a, 2906 (osteology); Stone, Proc. Ac. Nat. Sci. 

 Pliila., 1894, 115-117, part (Mauritius; crit.). — Micranous te-nuirostris Mathews, Birds 

 Australia, ii, 1912, pi. (116) facing p. 4\4.— Megalopterus tenuirostris tenuirostris 

 Mathews, Birds Australia, ii, pt. 4, Nov. 1, 1912, 416 (Seychelles, breeding). 



cMicranous worcesteri McGregor, Phihppine Journ. Sci., Sec. D, vol. vi, 1911, 185 

 (Cavalli, Sulu Sea). — Megalopterus minutus worcesteri Mathews, Birds Australia, ii, 

 no. 4, Nov. 1, 1912, 423 (Philippines). 



