226 POEMICAEIID^. 



comes much better in Myrmelastes near Gymnocichla. The tarsi are too long for 

 Thamnophilus, and they are covered at the back by a single shield, and not a number 

 of scutella, as in Thamnophilus. The feathers of the front portion of the head are 

 thin and scattered, showing a tendency towards the bare head of Gymnodchla. The 

 frontal feathers of Pyriglena are full and dense, but Gymnocichla is not distantly 

 related to that genus, in which Mr. Sclater originally located the female when he 

 described it as Pyriglena ellisiana ^. 



2. Myrmelastes lawrencii. 



Myrmelastes corvinus, Lawr. Ibis, 1863, p. 182 ^ (nee Thamnophilus corvirms, Gould) ; Ann. Lye. 



N. Y. viii. p. 7 \ 

 Gymnocichla 7mdiceps, Salv. P. Z. S. 1870, p. 195 (partim) ' ; 1874, p. 317 \ 

 Thamnophilics immaculatus, Sol. Cat. Birds Brit. Mus. xv. p. 189 (partim) '. 



Niger, unicolor, macula celata dorsaii et tectricibus alarum apicibus anguste albis : rostro nigro, pedibuB 

 obscure corylinis. Long, tofca 6'0, alas 3"0, caudse 2-45, rostri a rictu 1*0, tarsi 1"15. (Descr. maris ex 

 Mina de Chorcha, Panama. Mus. nostr.) 



2 adbuc nobis ignota. 



Hah. Panama, Chiriqui ^, Mina de Chorcha (Arce), Lion Hill (M'Leannan ^ ^). 



Mr. Lawrence's Myrmelastes corvinus was placed by Mr. Sclater, following Salvin *, 

 as a synonym of Gymnocichla nudiceps ^, but a re-examination of the question makes 

 us believe that this is not its true position. On carefully comparing all our specimens 

 called Thamnophilus immaculatus and Gymnocichla nudiceps we find two adult males 

 agreeing with one another, and differing in several particulars from both those birds. 

 There is no white margin towards the base of the wing as in T. immaculatus, and the 

 lesser wing-coverts are edged with white and not black as in that bird ; moreover, they 

 are smaller, and have a shorter tarsus. From G. nudiceps they differ in having the 

 crown feathered, the forehead alone showing scanty feathering ; the wing-coverts have 

 less white, the larger ones being wholly black. 



Mr. Lawrence's description ^ was based upon a young male in changing plumage, 

 the wing-coverts being tinged with rufous ; except so far as this rufous colouring goes, 

 our adult birds agree very closely ■with the type, which, through the kindness of the 

 authorities of the American Museum of Natural History, is now before us. 



The peculiarities of this bird are best recognized by placing it in Myrmelastes, and 

 by removing Thamnophilus immaculatus to the same genus. These two birds, with 

 some others, thus form a genus allied to Gymnocichla in which the feathers of the 

 forehead and lores are so thin as to allow the skin beneath to be seen. This feature 

 is a step in the direction of the bare head of G. nudiceps, G. chiroleuca being some- 

 what intermediate. 



It unfortunately happens that Mr. Lawrence's name clashes with Gould's Thamno- 

 philus corvinus, a synonym of T. leuconotus, which we now remove from Thamnophilus 



