BIRDS 361 



ters. Rump paler brownish, with indistinct darker central areas to 

 the feathers. Feathers of top of head with wide grayish-brown mar- 

 gins, narrow, elongate, dusky central parts. Hind neck with a light 

 brownish-gray collar. A pale supraorbital stripe of the same color 

 as the nuchal collar reaching to the latter from back of the nostril. 



Lesser and middle wing coverts light brown with pale brownish- 

 gray edgings. Greater wing coverts darker brown with narrow buffy 

 edgings and wider ashy tips. Primaries dusky brown with narrow 

 edgings of pale grayish-brown ;tips with slightly wider edgings of 

 ashy. Secondaries lighter brown with narrow pale brown edgings. 



Tail dusky brown, feathers with very narrow pale brownish borders, 

 ashy toward the bases. Under surface of feathers paler, slaty. All 

 the rectrices except the middle pair with a terminal spot of white on 

 the inner web ; spots of outermost feathers largest, about twenty 

 millimeters in length, decreasing successively in size on the other feath- 

 ers toward the middle ; spots of feathers next the middle pair always 

 very small, gone entirely when these feathers are much worn. 



Lores, suborbital and auricular regions brownish-black. A white 

 line just below edge of under eyelid. A narrow dusky malar stripe. 

 Entire under parts dull whitish. Sides and flanks with dark brown 

 streaks. Sides of lower breast with a few rather large spots of brown 

 on the centers of the feathers ; these spots rounded in outline behind, 

 emarginate anteriorly. A slight brownish tone on feathers of lower 

 part of breast, forming an indistinct band connecting the spotted 

 areas of each side. 



In coloration, especially in the presence of the spots of the sides of 

 the breast, this form resembles the Hood race JV. macdonaldi more 

 than it does any other. The spots in the Chatham form, however, 

 are not invariably present ; in one specimen that we have they are en- 

 tirely absent. The species is separated specifically from N. macdon- 

 aldi by the smaller size of the bill. 



This species is very closely related also to the form inhabiting Inde- 

 fatigable, but is always distinguishable from the latter by the pres- 

 ence of the maxillary stripes. In the color of the back N. adamsi 

 is paler than any other form of Nesomimus on the archipelago, but 

 in this respect it intergrades with N. melanotis dierythrui. It is in- 

 termediate between the forms having spotted breasts and those whose 

 breasts are plain, and thus has given rise to two lines of differentia- 

 tion. Along one line the dark maxillary stripes have been retained 

 and the back has taken on a dusky rather than a brown tone ; along 

 the other the brown tone of the back has been retained but the maxil- 



