12 Ridgway American Families of Oligomyodian Passer es. 



(3) The Elaininse restricted by elimination of the genera 

 Rhynchocyclus , Legatus, Myiozetetes, Conopias, Pitangus, Sirystes, 

 and Myiodynastes, which, except the first (referred to the Eus- 

 carthminae), should constitute a subfamily Pitanginae, morpho 

 logically intermediate between the Elaininse and Tyranninae, 

 and doubtfully separable from the latter. 



In my opinion these suggested modifications in the arrange 

 ment of the Tyrannidae are, in the main, entirely justifiable ; but 

 I am convinced that they are but a step toward much more 

 radical changes which will be necessary before a satisfactory 

 exposition of the phylogeny of the group can be made; and, 

 while not prepared to forecast these with any degree of certainty 

 will express my belief that (1) the genera Agriornis and Musci- 

 saxicola are each quite sui generis and are not by any means as 

 closely related to Tasnioptera as the latter is to Tyrannus ; and 

 (2) that a considerable number of genera do not belong to the 

 Tyrannidae at all but must be transferred to other groups, since 

 in none of them is the tarsal envelope exaspidean, the only ex 

 ternal character except that of slight syndactylism (very variable 

 within the group) which can be said to be really diagnostic of 

 the family. These genera are (1) Lawrencia which has a typic 

 ally Oscine tarsus and is without doubt a member of the Vire- 

 onidae. (2) Stigmatura, (3) Hapalocercus, and (4) Habrura, 

 which have taxaspidean tarsi; (5) Muscigmlla, (6) Sirystes, 

 (7) " Myiarchus " validus and (8) Ramphotrigon, which have 

 essentially holaspidean tarsi; (9) " Pogonotriccus " zeledoni, 

 (10) " Myiopagis " gaimardi, (11) Tyrannulus elatus, (12) 

 " Tyrannulus" (i. e. Microtriccus) semiflavus and brunneicapillus, 

 and (13) Ornithion inerme, which have essentially pycnaspidean 

 tarsi, and (14) Culicivora, which has non-exaspidean tarsi and 

 only ten rectrices. 



These genera, which I conclude do not belong to the Tyran 

 nidae, unless some new definition of the family be made, may 

 be again referred to in order to show more clearly why they 

 should be excluded from the group under consideration, as at 

 present susceptible of definition. 



1. Lawrencia Ridgway. 

 (Type Empidonax nanus Lawrence.) 



This genus has a typical Oscine acutiplantar tarsal envelope. It has ten 

 obvious primaries, of which the tenth (outermost) is about half as long as 



