Osteoloyy of the Numididce. 3 il 



outward in an U-shaped fashion as they are in N. mitrata 

 &c. Gallus is naturally more like tlie latter in this feature. 



§ The Fore Limb. 



The only detectable difference of note has already been 

 pointed out by Prof. Huxley. This is the absence in Numida 

 of a backward process of the second metacarpal. It is to be 

 found in Gallus as in Gallinaceous birds generally. 



It may be convenient, perhaps, before proceeding to con- 

 sider the osteology of the hybrid Guinea-fowl, to abstract 

 from the furegoing a tabular statement of the differences 

 between the species of the genus Numida, which allow it to 

 be divided, at any rate, into subgenera. The characters of 

 Numida proper and Gutter a will be then as follows : — 



GuTTEEA (including the species cristatn, eduardi, pnchera)ii*) : — • 



Trachea convoluted in both sexes and received into a bony dilatation 



of the clavicular symphysis. 

 Sternum without pneumatic foramen at base of manubrium, the 



carina much cut away anteriorly. 

 Ilia squarelj^ truncated behind. 

 Nasal processes of premaxillae very long. 



Numida (including the species vulturma, mitrata, ptilorhyvcha, 

 meleagris) : — 

 No convoluted trachea or bonj^ box upon the clavicles. 

 Sternum with pneumatic foramen at base of manubrium, the carina 



not much cut away anteriorly. 

 IHa with slightly developed posterior processes. 

 Nasal processes of premaxillse not so long as in Gidtera. 



§ Osteology of the Hybrid. 



Unfortunately, as already stated, several important regions 

 of the hybrid were wanting, so that my comparisons are not 

 so complete as 1 could wish. In the vertebral column the 

 only diagnostic feature which I was able to observe 

 concerns the sacral vertebrse. Here, as in Numida, the third 

 and fourth vertebrse after that bearing the last rib were 



* ry. W. A. Forbes, P. Z. S. 1882, p. 347. 



