372 Sans Graf von, Berlejpsch : 



ON THE GENUS ELAENIA Sundev. 



BY 



Hans Graf von Berlepsch. 



Although the genus Elaenia has already often received the 

 special attention of ornithologists interested in Neotropical 

 ornithology, there is apparently still so much confusion or 

 uncertainty about some sj;>ecies belonging to it that a 

 thorough and critical revision of the whole group should not 

 be out of place. I have therefore made these birds the object 

 of a more special study, and now propose to publish the 

 result of my investigations. I feel sure that my essay is still 

 far from being exhaustive and satisfactory in every way, 

 nevertheless I hope that it will contribute to a better under- 

 standing of the more obscure species of this genus. 



My studies have been supported chiefly by the large series 

 of EÌ 'aenia -sldns in my own collection, numbering now about 

 380 specimens. 



Unfortunately I have not been able to examine some species 

 which are not yet represented in my collection, and regarding 

 specimens of the martiniea group from the West Indies, and 

 the viridicata group as represented by forms from Mexico and 

 Central America, the material at my disposal was a rather 

 scanty one. I must leave it to a future worker to fill up the 

 gaps which may be observed in my treatment of the last- 

 named groups. 



My best thanks are due to the Hon. Walter Rothschild, 

 Dr. E. Hartert, and Mr. C. Hellmayr for the loan of 

 specimens and books, and for other useful information about 

 the subject. 



In the following pages 49 different forms of Elaenia are 

 admitted, of which 18 are considered to be subspecies, and 

 have received a trinomial appellation, so that there remain at 

 least 31 well-marked species of this genus. Nine subspecies 

 are described as forms new to science. 



