1887.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 93 



Heraignathus obscurus (Gmel.)- 

 Green Sickle-bill. Iwi. 



1788. — Certhia obscura Gmelin, S. N., I., p. 470. — ? Hemignathus obscurus Lichtenstel\» 



Abli. K. Akad. Berliu, 1838, p. 449, tab. v, fig. 1 (1839).— Cassix, U. S. Espl. 



Exp. Mam. Oru., p. 178 (1858).— Dole, Proc. Boston Soc. N. H., XII, 1869, 



p. 298, Extr. p. 5. — Id., Hawaiian Almanac, 1879, p. 45. — Sharpe, Cat. B. 



Brit. Mus., X, p. 4 (1885). 

 1859. — Drepanis {Hemignathus) elUsiaiia, Gkay, Cat. B. Trop. Isls. Pacif., p. 9. 



Two birds which Mr. Knudsen desiguates as male and female I refer 

 with a little doubt to Latham's " Hook-billed Greeu Creeper," upou which 

 Gmelin based his Certhia obscura. The length of the bill alone, as given 

 by Latham (1^ inches), proves, beyond a shadow of doubt, that Gray 

 was wrong in referring C. obscura to Vestiaria coccinea. Having only 

 Kauai birds before me, I can, of course, express no opinion in regard 

 to possible representative races on the other islands on which this spe- 

 cies likewise occurs. I may remark, however, that Latham describes 

 his bird as "in general olive green, palest beneath, and somewhat in- 

 clined to yellow," while Knudsen's birds are decidedly sulphur yellow 

 underneath; on the sides washed with olive. The bird from Oahu, 

 judging from Lichtenstein's descriptions and figure, differs from mine 

 in being much less yellow on the under surface, and in having the abdo- 

 men and under tail-coverts Isabella color and not olive yellow, but an 

 actual comparison can only decide whether there are two distinct forms 

 or not. 



Generally this bird is referred to the same genus as Hemignathus luci- 

 dus, but with doubtful propriety, as I think.* The bills in this group 

 of birds have served as the chief character for the establishment of 

 genera, and if we recognize more than one genus of Drepauine birds, 

 the two species of Reterorhynchus with their unique bills should cer- 

 tainly stand alone. With specimens in hand Mr. Sharpe would never 

 have included H. obscurus in a genus which he defines as having the 

 "upper mandible nearly twice the length of the lower one" (Tom. cit. 

 p. 2, Key to Genera), for the species in question has "both mandibles 

 of nearly the same length," the difference being about one-tenth the 

 chord of the exposed culmen, or proportionately the same as in Vestiaria 

 and Himatione. 



Whether the present bird, on the other hand, may not be strictly 

 congeneric with Brepanis pacifica I am unable to say positively, but, 

 judging from the descriptions and figures of the bill of the latter, I feel 

 confident that no great violence would be committed in uniting these 

 "Great Hook-billed Creepers" under the term Drepanis. 



The two specimens sent by Mr. Knudsen are identical as far as color 

 is concerned, but ^STo. 110044 has the bill less curved and shorter than 

 the other specimen, a difference which may perhaps be due to sex. 



*From the wording of the phrase in which Lichtenstein proposes the generic name 

 Eemignathus, it is evident that H. obscurus is the type and not H. hicidus, as gen- 

 erally stated. 



