104 ALBATROSS EXPLORATIONS, BIRDS RIUGWAY. 



Adult female (No. 116004, Hood Island, Galapagos, April 7, 18S8): 

 Similar to the male described above, but slightly smaller, bill straighter, 

 and under parts more tinged with brown, as well as more distinctly 

 spotted across chest. Length (skin), 10.00; wing, 4.55: tail, 4.25; exposed 

 cuiinen, 1.23; bill to rictus, 1.58; tarsus, 1.45. 



Four additional adult males agree essentially in coloration with the 

 one described, and measure as follows: Length (skin), 10.00-10.50; wing, 

 4.60-5.05; tail, 4.40-4.<i0; exposed oilmen, 1.27-1.35; bill to rictus, 

 1.55-1.65; tarus, 1.50. 



This fine new species is named after Cul. Marshall McDonald, L T . S. 

 Commissioner of Fisheries. 



4. Nesomimus personatus sp. nov. 



Sp. char. — Similar to X. melanotis (Gould), but much larger and 

 darker, with sides and flanks more tinged with brown. 



Hab. — Abingdon Island, Galapagos. 



Adult male (type, No. 116098, Abingdon Island, Galapagos, April 16, 

 1888; U. S. S. Albatross): Pileum, hind-neck, back, scapulars, wings, 

 and tail* dull blackish, the feathers indistinctly margined or edged 

 with dull grayish brown, these edgings much wider and more distinct 

 on wing and tail feathers ; feathers of hind-neck ash-gray beneath the 

 surface; lower back, rump, and upper tail-coverts dull grayish brown, 

 the feathers darker centrally, forming indistinct streaks; middle and 

 greater wing-coverts broadly tipped with dull white, forming two dis- 

 tinct bauds across wing; remiges rather broadly margined at tips with 

 dull light brownish gray (more brownish on tertials); three outer tail- 

 feathers broadly tipped with pale grayish brown (fading into dull white 

 exteriorly), this color confined to the inner web on third feather; lourth 

 feather with a more restricted and less definite lighter terminal space, 

 and two middle pairs merely fading at tips into dull grayish brown 

 edged with dull whitish. A superciliary stripe of dull grayish white, 

 narrower, whiter, and more sharply defined over lores ; lores, suborbital 

 region, and auriculars dull black, forming a conspicuous patch along 

 side of head; malar region, sides of neck, and lower parts white, the first 

 speckled with dusky, the second spotted with same posteriorly, and 

 the latter tinged with light brownish, except on chin and tliroat, the 

 sides aud flanks very distinctly washed or suffused with brown, the 

 latter broadly streaked or striped with dusky. Bill black, inclining to 

 horn-color at tip of upper and base of lower mandible; legs and feet 

 brownish black. Length (skin), 9.30; wing, 4.50; tail, 4.15; exposed 

 oilmen, 1.00; bill from rictus, 1.35; tarsus, 1.43; middle toe, .87. 



Adult female (No. 116099, same locality, etc.): Essentially like the 



*The specimen was molting when shot, though the new plumage had been mostly 

 assumed; consequently, in this description, the duller, faded, coloration of the old 

 feathers is ignored. 



