GALLI 303 



3. Furcula weak and straight (viewed laterally), with 

 straight rod-like hypocleidium. 



In the remaining gallinaceous birds the preacetabular 

 length is greater than the postacetabular (equal in Tetrao 

 eiipido) ; the postacetabular area is broader than it is long ; 

 the contour of the furcula is curved, with an expanded 

 hypocleidium. The series of birds which have these cha- 

 racters may be divided into the galline and the tetraonine 

 type. 



In the former the postacetabular region is only moderately 

 broad ; the hypocleidium is oval in contour ; the tarso- 

 metatarsus is more than half as long as the tibia, and there 

 are a number of smaller osteological marks. 



In the grouse-like birds the postacetabular region is very 

 broad ; the hypocleidium has a triangular form, and the 

 tarso-metatarsus is not half as long as the tibia. I do not 

 give HUXLEY'S characters in detail, since he has pointed out 

 that the two series meet among the partridges and quails, and 

 cannot thus be sharply marked off. 



The Alectoropodes have a range which is related to their 

 anatomical differences, as have the Peristeropodes. The 

 Meleagridse are confined to America, the Numidida? to 

 Africa, the Phasiaiiida3 to the Oriental region just encroach- 

 ing upon the Palaearctic, while the Tetraonidse are Palsearctic 

 and Nearctic. 



The Galli seem to be undoubtedly an ancient group of 

 birds, a view which is upheld by their points of likeness to 

 many diverse groups. 



That they are an ancient group is also shown by their 

 quintocubitalism, the primitive character of the gut con- 

 volutions, the often complete muscle formula, and the 

 existence of basipterygoid processes. The existence of these 

 structures has led to their comparison with other groups of 

 birds. Less weight, however, appears to be due to these 

 more general points of resemblance than to other slighter 

 but equally constant similarities. The existence of the 

 entepicondylo-ulnaris muscle is an example to the point. 



