A MONOGRAPH OF THE FLYCATCHER GENERA HYPO- 

 THYMIS AND CYANONYMPHA. 



By Harry C. Oberholser, 



Assistant Ornithologist, Department of Agriculture. 



Among the many East Indian birds of Dr. W. L. Abbott's collect- 

 ing, now in the U. S. National Museum, that Mr. Ridgway, the curator 

 of birds, has referred to the writer for determination, are a consider- 

 able number of blue flycatchers of the genus Hypotliymis. These 

 specimens are largely of forms more or less nearly related to Hypo- 

 tlujmis azurea; and in order satisfactorily to work out their relation- 

 ships it has been necessary to make as thorough an examination as 

 possible of all the species of the genus. 



The genus HyjJothymis at present consists nominally of 1 1 species 

 and subspecies. Of these, HyjiotJiymis sujjerciliaris and its close 

 ally, H. samarensis, are clearly out of place in Hypothymis, but even 

 more so in RMjndura, where some recent authors have placed them. 

 It seems necessary, therefore, to create for them a new genus, which 

 I hereinafter accordingly do. Nor am I fully satisfied regarding the 

 correct position of Hyi)othymis rowleyi, but leave it here pending fur- 

 ther investigation. The bird from Celebes, Hypothymis puella 

 puella^ and its subspecies from the Sula Islands, Hypothymis puella 

 hlasii, are very distinct from the other members of the genus, as is 

 also Hypothymis abhotti Richmond. 



All the other forms, including several new ones, are clearly geo- 

 graphical races of Hypothymis azurea, though some of them pass for 

 species. We are now able to distinguish sixteen forms of Hypo- 

 thymis azurea, most of them island races, and, with two excep- 

 tions, of comparatively limited distribution. Each intergrades with 

 some other, either through individual variation or (in one instance) 

 continuity of range, so that there is just cause for considering them 

 all subspecies. ^Most of the color characters exist only in the males, 

 the females in nearly every case being separable, if at all, only 

 by size, so that in the following pages the diagnoses apply to the 



Proceedings U. S. National Museum, Vol. 39— No. 1803. 



585 



