l«^S- PROCEEDTXGS OF THE XATTOXAL ^^USEr^f. 521 



;i!i(l (aii deep black instead of ^'rayisli brown, llie wiiio- feathers (both 

 reiiii.ues and coverts) with inner webs and bases laryely and abruptly 

 l)ure white, and the upper tail-coverts and flanks marked with ^iittate 

 or wedjxe- shaped spots of black. 



Ti/pc. — ISTo. 128701, U.S.IST.M., adult male, Assumption Island Indian 

 Ocean, September 18, 1892; Dr. W. Tj. Abbott: Head, neck, back, rump, 

 upper tail-coverts, and entire under ])arts ])ure white; scapulars and 

 Avinu' coverts pure white basally, .urayish black terminally, the former 

 mostly concealed, but fre(|uently exiwsed as angular spots or streaks, 

 particularly on the lesser and middle wing-coverts; greater coverts with 

 inner webs pure white, except at tip; remiges and primary coverts black 

 superlicially, but inner webs of secondaries chiefly (those of innermost 

 feathers wholly) pure white, and those of the primaries also largely pure 

 white, this color reaching to the shaft on the basal portion of the first 

 quill, which also has the outer web white, and the shaft yellowish white, 

 at base; on the innermost ])rima.ry the white forms a broad edging which 

 extends nearly to the tip, gradually running out to the edge, but at the 

 base occupying the entire width of the web. Tail deep black, the feath- 

 ers (except middle pair) sharjily tipped with pure white, and broadly 

 edged with the same at tlio base. Each of the upper tail-coverts has 

 a large wedge-shaped median spot of black, and many of the feathers 

 of the flanks are similarly marked. '-Iris dark brown; feet leaden 

 gray, lower parts of webs black; tip of bill [for about 1 inch] black; 

 [rest of I bill fleshy white; orbital skin black; gular pouch light green." 

 (Abbott, IMS.) 



Total leiigth (skin), about 28 inches; wing, 18; tail, 8.40, outer feath- 

 ers 3.20 shorter; culmen, 4.40; depth of bill at base (in front of lores), 

 l.Go, width at same point, 1.22; tarsus, 2; middle toe, .'150. 



This fine species is a little larger than S. cyanops^ and of similar gen- 

 eral appearance, but ditfers very much both in form and coloration. 

 The bill is much heavier than in that species, for while but little longer 

 it is altogether deeper and broader through the base. The serrations 

 of the tomia are also much coarser. The tarsus is decidedly shorter, 

 but the toes much longer, than in H. cyanops, and the covering of both 

 legs and feet is far rougher than in that or any other species of the 

 genus. As to coloration, the most consiucuous features are the sharply 

 diifined Avedged-shaped black markings on a pure white ground, on the 

 upper tail-coverts and flanks, the extensively white inner webs of the 

 remiges, and the positively black, instead of brown, general color of 

 wings and tail. Wherever the white and the black come into Juxtapo- 

 sition there is always a bold line of junction, and in no case a gradual 

 shading together of the two colors. 



"Creole name, ' jPo?f ha-nf.' A few breed on Assumption. Said not to 

 be found on any other island in these seas." (Abbott, MS.) 



Judging from the description in Taczanowski's Ornitholof/ie du Ferou^^ 



'Vol. ITT, ]i. 488. 



