298 Bangs, Birds from. Western Costa Rica. [juiv 



in the Rio Grande region and secured the large series listed above. I was 

 much surprised, however, on comparing these skins with a series from 

 Loma del Leon, Panama, taken some years ago by Brown, to find the Costa 

 Rican form so different. The female of the Costa Rican bird can be told 

 at a glance by its much deeper and more intensely ferruginous general 

 coloration; the male, as might be expected in an almost wholly black bird, 

 is not different in color, but can be distinguished by having a longer wing 

 than true G. nudiceps, this difference being probably greater than the 

 measurements indicate, because the Boruca series is in rather worn summer 

 plumage, whereas the Panaman specimens, with which I compare them, 

 are in fresh, unworn spring plumage. 



Formicarius hoffmanni hoffmanni (Cab.). Eighty specimens, adults 

 of both sexes, and one young female, Boruca, Paso Real, Pozo del Rio 

 Grande, Lagato and Barranca, April-August. 



A young female, in nestling plumage and not full grown, is similar to 

 the adults in color, except in being duller with all the colors more blended, 

 the chestnut patches on sides of neck and crissum less strongly marked, 

 and the tail blackish only at tip. 



One specimen has the whole throat white, marked with small black dots. 

 I had already another skin just like it from Chiriqui, and Ridgway described 

 a specimen, supposed to be a young male, of F. nigrifrons (Proc. U. S. 

 Nat. Mus., Vol. XVI, p. 672, 1893) in similar plumage. 



That these black spotted, white-throated birds do not represent the 

 normal young plumage is proved by the presence in this series of the young 

 female described above which has the throat just as in the adults. More- 

 over, my two specimens do not appear to be young — ■ that is not nestlings 

 — being so far as one can judge by the prepared skin, full grown and 

 mature, and it remains to be found out just what stage of plumage these 

 white-throated individuals, recorded now in two species of Formicarius, 

 represent. 



Grallaria lizanoi Cherrie. Twenty-four specimens, both sexes, Boruca, 

 Paso Real, and Pozo del Rio Grande, April-August. 



Dendrocolaptid.e. 

 Synallaxis albescens latitabunda subsp. nov. 



Five specimens, both sexes, three adults and two young, Boruca, Paso 

 Real and Barranca, May-July. 



Type, from Boruca, Costa Rica, No. 19064, cT adult, coll. of E. A. and 

 O. Bangs. Collected May 31, 1906, by C. F. Underwood. 



Characters. Similar to Synallaxis albescens albigularis Scl. of north- 

 eastern South America, but differing in having red of crown much more 

 extended, reaching backward over entire occiput; the white throat more 

 sharply defined, and gray band across chest more pronounced; the red- 

 brown of wings and crown rather less ochraceous, more bricky. 



