518 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



with a prominent angle near the base, anterior to which the edge is 

 decidedly concave; maxillary tomia with a decided notch near the 

 base, immediately above the mandibular angle; gonys very long (about 

 equal to the exposed portion of the culmen). Nostrils exposed, small, 

 longitudinal, occupying less than the lower half of the nasal foss^. 

 Tarsus a little longer than the middle toe and claw, divided into about 

 six segments, but these entirely fused on the outer side, except the lower 

 one, which is distinct; lateral toes equal, the points of their claws fall- 

 ing short of the base of the middle claw; inner toe entirely separated 

 at the base from the middle toe, and outer with only its first phalanx 

 united; hallux about equal in length to the lateral toes, but much 

 stronger, its claw decidedly larger than that of the middle toe. Wing 

 decidedly longer than the tail, very concave beneath, the seventh, 

 sixth, and fifth primaries nearly equal and longest, the eighth very 

 little shorter, the ninth about equal to the third. Tail about equal to 

 the wing measured to the ends of the secondaries, nearh" even or very 

 slightly rounded, consisting of twelve rectrices, which are acute, but 

 not stiffened at the points; the outer web of the intarmedim broader at 

 the base than the inner web. 



As characters additional to those given in the above diagnosis, it 

 maj' be stated that the bill is slightlj' notched near the tip, that the 

 rictal bristles are so mmute as to be hardlj^ perceptible, and that the 

 posterior face of the tarsus, on both sides, is entirelj^ undivided. 



Range. — Highlands of Costa Rica. (Monotypic.) 



The adult male of Acantliidoiis halrdl resembles \%\y closely in col- 

 oration that of liaplospiza unlcolor, of Brazil, but is darker and less 

 of a bluish cast, both above and below, and has the mandible chieflj' 

 light colored. Not having a specimen of the Mexican H. uniformis, 

 I am unable to point out wif^ exactness the differences from that spe- 

 cies; but judging from the description and remarks given by Messi'S. 

 Salvin and Godman ' it seems to come much closer to that species, if 

 it be not actually the same. It would appear, however, to have decid- 

 edly a shorter wing and longer tail, and longer tarsus than thai, bird. 

 Whether or not it is the same species or congeneric with H. uniformis., 

 there can be no doubt that it is generically distinct from H. unicolor, 

 which has the bill much shorter and more typicalh' Fringillint, the 

 tarsi shorter, and the nostrils moi'e exposed. There can, I thiuK, be 

 no question that Acanthidaps comes very near to Ilajilospiza, and I am 

 inclined to believe that the so-called S. uniformis belongs to Acan- 

 tliidops and not to Haplospiza, since Messrs. Salvin and Godman' say 

 that its chief differences from II. unwolor consist in "a larger bill and 

 longer wings and stronger feet," as well as " rather darker" coloration. 

 If this view of its relationship proves correct, we would then have a 

 Middle American genus, Acanthidops, and a related Brazilian genus, 



' Biologia Centrali-Americana, Aves, pp. 366, 367. 



