552 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



[Anous] stolidus subep. galapayrnsis Forbes and Robinson, Bull. Liverp. Mus., 



ii, no. 2, 1899, 5G. 

 Anous galapagoensis Bauk, Am. Nat., xxxi, 1897, 782 (Duncan Island), 783 



Gardner-near-IIood Island). 



Genus MEGALOPTERUS Boie. 



Megalopterus Boie, -Isis, 1826, 980. (Type, by monotypy, Stinia tenuiwstris 



Temminck.) 

 Mcranotts" Saunders, Bull. Brit. Orn. Club, no. xxiii, Jan. 29, 1895, p. xix; 



Ibis, April, 1895, 276. (Type, by original designation. Sterna tcnuirosiris 



Temminck.) 

 Anousella b Mathews, Birds Australia, ii, pt. 4, Nov. 1, 1912, 412, in text. (Type, 



by original designation, Anous Icucocapillus Gould.) 



Medium-sized or rather small Sternidse (wing 210-225 mm.) 

 resembling Anous, but with gonys longer than mandibular rami 

 (instead of shorter), maxilla not decurved distaUy, and tail less 

 strongly graduated and less deeply forked. 



Bill relatively slender, longer than head, nearly straight (the 

 exposed culmen, however, shorter than middle toe with claw), its 

 greatest de})th equal to only one-fourth (or less) the distance from 

 anterior end of nostril to tip of maxilla; culmen straight for most of 

 its extent, very slightly decurved distally; gonys longer than man- 

 dibular rami, straight, slightly ascending terminally, rather prominent 

 basally; nostril narrowly elliptical or linear, longitudinal, almost 

 wholly anterior to mental antia; anterior outline of feathering on 

 forehead and lores slo})ing baclvward and dt)wnward from frontal 

 antia (at base of culmen) to rictus, without trace of loral or latero- 

 frontal antia. Wing long and ])ointed, the longest primary (outer- 

 most) exc-eeding distal secondaries ])y decidedly more than half the 

 length of folded wing, but by very much less than twice the distance 

 from tij^s of distal secondaries to })end of wing. Tail decidedly more 

 than half as long as wing, slightly forked and moderately grachiated, 

 the lateral pair of rectrices about three-fourths as long as the longest 

 (third and fourth pairs, counting from middle), the middle ])air 

 shorter than longest by much less than half the distance between 

 tips of longest and shortest rectrices; rectrices slightly but distinctly 

 tapering terminal!}^, with rounded tips. Tarsus decidedly shorter than 

 middle toe without claw; outer toe as long as middle toe or very 

 slightly shorter; webs between anterior toes with anterior edge but 

 slightly excised. 



Plumage and coloration. — Plumage blended throughout as in Anous, 

 with occipital feathers not elongated,. Adults plain dusky, except 

 pileum and nape, which are grayish or whitish. 



Range. — Tropical seas of l)oth hemispheres. (Two species?) 



o MiKpos, small; -|- Anous (avoos, silly, stupid). (Richmond.) 

 b Anous (dvovs. foolislri-j-ella. (Mathews.) 



