140 VISCOUNT WALDEN ON THE BIRDS 
Verreaux had ascertained by dissection that H. sericeus and H. erythrogenys were male 
and female of the same species. Perhaps it will be eventually shown that the adults of 
both sexes do not differ in coloration, and that the rufous cheeks are a sign of nonage 
common to both sexes. Dr. Meyer’s examples are all in the sericeus plumage; and some 
are marked by him as male, and others as female. In one of the latter the wing measures 
a full half inch longer than in the males; and the other dimensions are proportionally 
greater. 
H. cerulescens evinces a somewhat analogous tendency, the white forehead and 
supercilium of the adults being rufous in a prior stage of plumage. And this is also to 
be observed in /7. eutolmus, where, however, the chin and throat are white in the young 
bird, instead of ferruginous as in the adult. 
On the authority of M. de la Gironniére (Bonite, /. c.) the Philippine Hieraz is stated 
to appear in Luzon only in the spring; and the inference is drawn that it is migratory. 
Dr. Meyer obtained his specimens in January and April. 
In the Hand-list (/.c.) Mr. G. R. Gray notes H. sericeus as occurring in North 
China. It is not included in either Mr. Swinhoe’s list (P.Z.S. 1871), or in that of 
M. Armand David (N. Archiv. Mus. vii.). Mr. Swinhoe, however, recently observed a 
species of Hierax in a collection made by Pére Heude near Shanghai (Ibis, 1873, p. 95); 
but he does not identify the species. 
Hierax melanoleucus, Blyth, is treated by Mr. Strickland (Orn. Syn. p. 104) as a 
synonym of H. sericeus, whereas the Assamese Hieras is a very distinct and well-marked 
species. It differs in having black cheeks, white lores, a white superciliary stripe 
continued along the sides of the head to the neck, white shoulder-edge and under 
shoulder-coverts, and in having all the rectrices except the middle pair with five or 
more white spots on their inner webs, and all the quills numerously barred with white. 
In the Philippine species the tail-feathers, quills, and under shoulder-coyerts are black, 
some of the quills being indistinctly mottled with dirty white. It possesses no super- 
cilium ; and the cheeks are white. 
ACCIPITRIN&. 
Lopnospiza, Kaup. 
11. LopHospiza TRIVIRGATA. 
Falco trivirgatus, Tem. Pl. Col. 303, “ Sumatra” (1824). 
Astur cristatus, G. R. Gray, Ann. N. H. xi. p. 371, “ Philippine Islands ” (1843). 
Hab. Philippines (G. 2. Gray). 
Mr. J. H. Gurney informs me that Philippine examples of this species are preserved 
in the Norwich Museum. 
