34 



ORNITHOLOGICAL P:XPLORATIONS. 



piece is shed first, aucl comparatively early, several specimens affording 

 evidence that it drops off before the birds leave the rookeries. The 

 material at hand also indicates that the outgrowth in spring and the 

 change of color of the basal parts of the bill takes place rather late and 

 very rapidly, much more so than the corresponding process in Lunda 

 and Fratercula. 



As to the condition of the bill and the basal part of the upper tomium 

 in winter, I refer to fig. 5, on plate iv, and to the following descrip- 

 tion of these parts which I took down from the fresh specimen (No. 

 92952) as follows : "The feathering at the base of the maxilla does not 

 (as in 8. pygmcca aud pnsilla) cover the tomium, which is soft and forms 

 a whitish, broadened lobe above the corner of the mouth." No corre- 

 sponding structure was observed in the other species. This soft lobe, 

 the "matrix" of the horny circular corner-piece, is hardly noticeable in 



the dried skins. 



List of specimens collected. 



Locality. 



Bering Island 



..do 



..do 



...do 



...do 



...do 



...do 



..do 



...do 



...do 



May 16, 

 June 4, 

 June 4, 

 May 16, 

 May 19, 

 June 14, 

 Dec. 2, 

 Jan. 1, 

 Jan. 18, 

 Mar. 1, 



1882 

 1883 

 1883 

 1882 

 1883 

 1883 

 1882 

 .1883 

 1883 

 1883 



cTad. 

 d'ad. 

 cTad. 

 ?ad. 

 (?)ad. 

 $ad. 



? 



9 



? 

 9 ad. 



m,m. . mm. 

 134 39 



134 

 134 

 138 

 133 

 134 

 125 

 126 

 133 

 135 



mm. 

 37 



No. 89097. — Iris white. Bill reddish orange ; tip homy white, shaded with dusky, on upper mandi- 

 ble. Feet light violet gray ; joints darker; webs hlackish ; tarsus and toes below black ; nails gray 

 at base, blackish at tip. 



No. 92955. — Iris white. Bill bright reddish orange ; tip horny brownish white. Feet light violet 

 gray ; joints darker. Crop and stomach empty. 



No. 92954. — Iris white. Color uf bill and feet as foregoing number, only that the fe«t have a more 

 pure bluish hue. Stomach empty. Very fat. 



No. 89096. — Iris white. Bill reddish orange; tip brownish gray ; tip of lower mandible somewhat 

 lighter; interiorof mouth white, with a slight tinge of flesh color. Feetlight violet gray ; jointsdarker; 

 web, soles, and nails black. 



No. 92S52. — Iris white. Bill horny brown ; both mandibles at base and the gonys lighter; soft edge 

 at base of upper mandible whitish ; interior of mouth white, faintly tinged with flesh color. Feet vio- 

 let pearly gray ; joints brown ; webs and soles dark brownish. Stomach empty. 



No. 92951. — Iris white. Bill horny brown ; tip of upper mandible more grayish; lower mandible 

 lighter, aluiost brownish flesh color. Feet bluish gia ■, a trifle darker and more viokt than in SivaO' 

 ihynchus pygmoeus ; joints brownish ; weba aud aolcs blackish. Extremely lean. 



