1876.] OF PASSERINE BIRDS. 517 



Passeres Oligomyodi. 



With a femoral artery. With a sciatic artery. 



Chiroxiphia linearis, Mio?iectes oleagineus, 



Chiromachceris vitellina, Tyranniscus vilissimus, 



Heteropelma vercepacis, Pitangus sulphuiatus, 



Tityra persona fa, Myiodynastes luteiventris, 



Hadrostomus aglaice, Empidonax minimus, 



Lipaugus sp., Myiarchus vrinitus, 



Cotinga cincta, Tyrannus melancholicus, 



Ghasmorhynchus nudicollis. Rupicola crocea, 



Pitta angolcnsis, 

 Pitta cyanura. 



I must mention also that in a specimen of the minute Mitre- 

 phorus phceocercus, it appeared to me that the artery of the leg was 

 the femoral ; hut T should like to see more specimens before I can 

 feel justified in disturbing any generalizations by using this single 

 example. 



All Acromyodian Passeres of species which I have examined, over 

 one hundred in number, possess the sciatic artery, including Menura 

 and Atrichia ; and the Tracheophonse quite agree with them in this 

 respect. Such being the case, it seems to me that from among the 

 Mesomyodian Passeres a small section may be divided off, including 

 the families Pipridse and Cotingidse, in which a characterizing feature 

 is the development of a femoral in place of a sciatic artery; and this 

 being the case, Rupicola must be removed from the Cotingidse. 



Although, as yet, our knowledge of the anatomical characters 

 which are the bases of the minor divisions of the Passerine group 

 is still so little advanced, nevertheless a rough sketch of the classi- 

 fication of the order, in which no attempt to fill-in details can be 

 made, is quite within our power. 



To commence with Midler's character depending on the situation 

 of the insertions of the syringeal muscles, Passerine birds fall 

 primarily into two main sections, the Acromyodi, in which the 

 intrinsic muscles of the voice-organ are fixed to the end of the 

 bronchial semirings, and the Mesomyodi, in which they join 

 them at or near their middle. The former group includes all the 

 true Oscines, together with Menura and Atrichia ; the latter the 

 Tracheophonse, together with those Passeres included by Midler 

 with the Picarise, as well as Pitta. 



The Mesomyodi fall into two groups, according to the situation 

 of the main artery of the leg. Those in which the sciatic is the 

 artery of the thigh may, because they therein agree with other 

 birds, be termed Homceomeri ; those in which the femoral artery is 

 developed, from being in this respect abnormal, may be termed 

 Heteromeri. 



Of the Homceomeri the Tracheophonee of Midler form a special 

 well-marked section, — the rest, including the Tyrannidee, Rupicola, 

 Pitta, forming a division which may be termed Haploophonse until 

 there is reason for further splitting them up. 



