MTEMELASTES. 225 



Myrmelastes cormniis, Lawr., and Myrmeciza exsul and its close ally M. sdateri seem 

 strictly congeneric. Thamnophilus leuconotus also belongs here. 



The larger black species are evidently closely allied to Gymnocichla, the chief 

 difference being in the feathering of the head, Gymnocichla having the crown bare, 

 thinly strewn with hair-like feathers ; a tendency to this denudation is shown in 

 Myrmelastes, in which the frontal and loral feathers are thin, leaving the skin visible, 

 which in all cases appears to be light blue in life, as in Gymnocichla. 



Myrmelastes, as we understand it, contains four or five species, of which four occur 

 within the limits of the southern section of Central America. All are forest-loving 

 terrestrial species, and all hang round the hordes of foraging ants (JEciton), feeding on 

 the insects started from their path. 



1. Myrmelastes immaculatus. 



Thamnophilus immaculatus, Lafr. Rev. Zool. 1845, p. 340*; Salv. Itis, 1870, p. 114^; P. Z. S. 

 1870, p. 194'; Berl. & Tacz. P. Z.S. 1883, p. 564*; Scl. Cat. Birds Brit. Mus. xv. p. 189°. 

 Pyriglena ellisiana, Scl. P. Z. S. 1855, p. 109, t. 100 \ 



Niger, margine alarum proximo et macula dorsali celata parva albis, rostro et pedibus nigris. Long, tota 6'5, 

 alse 3-3, caudse recti, med. 3'1, rectr. lat. 2*1, rostri a rictu 1-0, tarsi 1"3. (Descr. maris ex Tiicurriqui, 

 Costa Eica. Mus. nostr.) 



§ saturate brunnea, subtus dilutior ; f rente, capitis lateribus et Cauda nigricantioribus, mandibula infra pallida. 

 (Descr. feminse ex Calovevora, Panama. Mus. nostr.) 



ffab. Costa Rica, Tucurriqui (Arce ^) ; Panama, Volcan de Chiriqui ^, Boquete de 

 Chitra, Calovevora ^, Calobre ^ (Arce).— Colombia ^ ^ ; Ecuadoe ^ * ^. 



Lafresnaye first described the male of this species in 1845 from Colombian speci- 

 mens 1, and the female also received a name from Mr. Sclater in 1855, based upon an 

 example in the British Museum from the same country^. The two. birds were 

 associated as sexes of the same species by Salvin in 1870 ^, on receipt of several birds 

 from Panama and Costa Rica, both males and females, sent us by our collector 

 E. Arce. 



The range of Myrmelastes immaculatus is somewhat restricted, and extends from 

 Western Ecuador northwards to Costa Rica. It is also found in the valley of the 

 Magdalena, as specimens are sometimes to be found in the trade collections of skins 

 sent from Bogota. Salmon, however, did not meet with it in the State of Antioquia, 

 nor did M'Leannan on the Isthmus of Panama. 



We are without any record of its habits, but may safely assume that it is an 

 inhabitant of the forest. Stolzmann's specimens were obtained at Chimbo, in Western 

 Ecuador, a heavily-forested district. That excellent collector noted the colour of the 

 iris as burnt-sienna, the naked part of the sides of the head greyish blue, brighter on 

 the auricular region, but nearly white in the female ^. 



Though placed in Thamnophilus by recent writers, we now consider that this species 

 BIOL. CENTK.-AMER., Aves, V^ol. II., March 1892. 29 



