Vol.^xyillJ Clark, The Classification of Birds. 377 



Femoral tracts long but narrow, and not very strong. 



Lower cervical tract similar to upper but the division is not so deep, 

 and the branches tend to diverge. 



Sternals broad (compared with the other tracts), continuous with or 

 separate from the lower cervical. 



Ventrals broad and continuous with the sternals, sometimes separated 

 from the latter, for some distance, joining near the furcula. 



This type characterizes the Rails. Cranes, Storks, Herons, 

 Bustards, and Flamingoes. 



Charadriiform. 



Upper cervical tract sharply defined, not very deeply forked, the 

 branches diverging. 



Dorsal tract more or less forked (toward rear), slightly if at all 

 connected with forks of upper cervical. 



Humeral tracts narrow. 



Femoral fairly strong, usually narrow and distinct. 



Lower cervical tract very deeply forked, continuous with sternals. 



Sternals moderate in size but strong. 



Ventrals narrow or only moderate!}' wide, well separated on the belly, 

 joining the sternals on the breast usually near the furcula. 



This type is shown by the Gulls, Terns, Plovers, Snipes, 

 Sandpipers, etc. 



Galliform. 



All the tracts broad, but usually well defined. 



Upper cervical tract usually niore or less merged with the dorsal, but 

 soinetimes more or less distinctly forked. 



Dorsal tract broad, sometimes very broad posteriorly ; often with a 

 mid-dorsal apterium ; occasionally connected with the femorals. 



Humeral tracts broad and very strong. 



Femoral tracts very large, sometimes uniting with the dorsal. 



Lower cervical tract rather deeply forked, the branches continuous 

 with the sternal tracts. 



Sternals very strong, widest anteriorly, connected with ventrals near 

 furculum or not at all. 



Ventrals narrow, not widely separated on belly, narrowest anteriorly, 

 united posteriorly in front of anus. 



This type is shown by the Gallinaceous Birds, Curassows, and 

 Tinamous. 



