lo8 ox THE OSTEOLOGY OF THE TRACHEOPHOXE PASSEKES. [Feb. 20, 



phaga there is a slender strip of muscle, un(ierl3-ing tlie clavicular 

 liead. which arises from the dorsal aspect of the acromion of the 

 scapula ; but this is of no importance. In these three genera the 

 brevis portion is still moderately well-developed, arising from the 

 OS hnmero-scapulare, and extending nearly as far downwards as 

 the middle of the shaft ; while the longus portion is very slender, 

 but remains fleshy up to the point of insertion, whereas in the 

 other genera i-eferi'ed to it terminates in a lojig tendon. 



With regard to the relationship of the " Tracheophonese " to the 

 remaining Passeres, it seems to me that we may regard this Sub- 

 order as one of three main branches of a common stem (see text- 

 fig. 52). One of the extremities may be called the Euryltemid 



Text-fig. 52. 



„ ... Passtres 



Forwicarudx Dendrocolaptidee Osciaes 



SjrnaJJaxida? 



Pipridae ni -i ■ -j \ « /f 



Cotmgidx^ \^^^^^^^ JenicideS. \ // y^Menuridse Tyraiuudis 



Pittida.- 

 Eiuylaeimdae 



Phylogenetic tree iiiflicating' the probable relationships of the 

 " Tracheophone " Passeres. 



branch ; therefrom have arisen the Pipridre, Cotingidfe, and 

 Philepittida^. The Tracheophone comes off, as it were, from the 

 axil of the Eurylaemid branch, while the third, forked at its base, 

 gives rise to the Tyrannidse and Pittidte on the one hand and the 

 Oscinine Passeres on the other. As to the position of the 

 Menuridfe 1 am in doubt at present, but probably they are an 

 offshoot of the Oscinine stem, low down. 



There is yet much work to be done among the non-oscinine 

 Passeres, but I believe that the present scheme is more nearly 

 phylogenetic than any which has preceded it. I am now engaged 

 on the " Tyrannine " branch, and hope soon to present a summary 

 of my labours thereon. 



