THE AUK: 



A QUARTERLY JOURNAL OF 



ORNITHOLOGY. 

 Vol. XXI. July, 1904. No. 3. 



THE BIOLOGY OF THE TYRANNID^ WITH 



RESPECT TO THEIR SYSTEMATIC 



ARRANGEMENT. 



BY DR. H. VON IHERING. 



The systematic arrangement of animals is usually based on 

 morphological characters only, but biological observations may 

 often give us precious hints which may help us to settle difficult 

 questions in this respect. Considering that the present systematic 

 arrangement of the genera belonging to the great family of 

 Tyrannidae is far from being a satisfactory one, I have thought 

 it useful to study in a comparative way the biology of the members 

 of this family. 



Of the four subfamilies accepted according to the classification 

 of Mr. Sclater, at least one seems to be unnatural as well as 

 regards morphological as biological characters ; that is to say, the 

 Platyrhynchinae. 



In my paper on eggs and nests of Brazilian birds (Revista do 

 Museu Paulista, IV, 1899, p. 226)1 described the nest and eggs 

 of Platyrhynchus mystaceus and expressed my surprise at their 

 great difference when compared with the nests and eggs of the 

 allied genera. Having obtained this year an authentic nest of this 

 species I am able to state that as regards the first described nest 

 there was a mistake. The nest of the above mentioned species of 

 Platyrhynchus, which will be fully described in Vol. V of the 



