158 ON THE OSTEOLOGY OF THE TRACHEOPHONE PASSERES. [Feb. 20, 



phaga there is a slender strip of muscle, underlying the clavicular 

 head, 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 humero-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 referred to it terminates in a lo^ig tendon. 



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

 remaining Passeres, it seems to me that we may regard this !3ul>- 

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

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



Text-fig. 52. 



. PassTes 



Formicarudx ^ Dendrocolaptids lOsciaes 



SynaJJaxidee 



Pjpridse 

 Cotingidas^ \f^'^^^^^^ Xenicid^ \ l\ .^Menuridce Tyramdda; 



ittidss 

 Evrylteinidas 



Phylogenetic tree inrlicatino; the probable relationships of the 

 " Tracheophoiie " Passeres. 



branch ; therefrom have arisen the Pipridse, Cotingidpe, and 

 Philepittidse, The Tracheophone comes off, as it were, from the 

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

 gives rise to the Tyrannidas and Pittidse on the one hand and the 

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

 Mentu'idfe I 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. 



