140 VISCOTJNT 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. 



E. coerulescens 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 H. entolmus, where, however, the chin and throat are white in the joung 

 bird, instead of ferruginous as in the adult. 



On the authority of M. de la Gironniere (Bonite, I. c.) the Philippine Hierax 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 (/. <?.) 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 Pere Heude near tShanghai (Ibis, 1873, p. 95); 

 but he does not identify the gpecies. 



Hierax melanoleucus, Blyth, is treated by Mr. Strickland (Orn. Syn. p. 104) as a 

 synonym of II. sericeus, whereas the Assamese Hierax 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-coverts are black, 

 some of the quills being indistinctly mottled with dirty white. It possesses no super- 

 cilium ; and the cheeks are white. 



ACCIPITRIN^. 



LoPHOSPizA, Kaup. 



11. LOPHOSPIZA TBIVIRGATA. 



Falco trivirgatus, Tern. PI. Col. 303, " Sumatra" (1834.). 



Astur cristatus, G. R. Gray, Ann. N. H. xi. p. 371, " Philippine Islands" (1843). 



Hab. Philippines {G. R. Gray). 



Mr. J. H. Gurney informs me that Philippine examples of this species are preserved 

 in the Norwich Museum. 



