1868.J 



PROF. HUXLEY ON THE ALECTOROMORPH^. 



2'J7 



varies a good deal both in the Megapodidce and in the CracidcB. 

 If we term the moiety of the dorsal asj)ect of the pelvis which is 

 bounded in front by a transverse line drawn through the acetabula 

 tlie postacetahidar area, each group will be found to present some 

 forms in which the postacetabular area is broad, and some in which 

 it is relatively narrow. 



ex 



m.x 



Fig. 1. The sternum of Crax gloUccra. — r. Rostrum, c.p. Costal process. 

 pi. o. Pleiirosteon. e. x. External xiphoid process ; and i. x, internal 

 xiphoid process of the metosteon. I. o. Lopliosteon bearing the carina 

 and ending behind in m. x, the middle xij^hoid process. » « The inner 

 notches. 



Fig. 2. The sternum of Lophophorus impeyanus. The letters as before, except 

 pt. 0, metosteon. 



Thus Talegalla has the postacetabular area broad, while Mega- 

 podius has it narrow. 



The Penelopince (Penelope, Oreophasis, Ortalida) have the post- 

 acetabular area broad; but in the Cracince {Crax, Pauxi) it is 

 narrow (figs. 3 & 4, p. 298). 



M. Blauchard has already indicated some of the differences be- 

 tween the Cracidce and the ordinary Gallinaceous birds. 



" Les types esseutiellement Amcricains, comme les Alectors, c'est 

 {i dire les genres Urax, Crax, et Penelope, s'oloignent a quelques 



