OSTEOLOGY OF BIRDS 22(-} 



figured several views of the skull of the young of Centrocercus 

 [pi. 5] ; the development of t4ie sternum of Centrocercus and the 

 figure of the skull of the adult, and also a figure of the dorsal 

 vertebrae [pi. 6] ; bones of the pectoral limb of the same bird 

 [pi. 7] ; the development of the pelvis of C e n t r o c e r c u s u r o - 

 phasianus [pi. 8]; bones of its pelvic limb, and the pygo- 

 style [pi. 9] ; three views of the skull, the mandible, the sclerotal 

 plates, and the humerus in Tympanuchus [pi. 10] ; views of the 

 ribs and sternum in Tympanuchus [pi. iij; views of the pelvis 

 and shoulder girdle in Tympanuchus [pi. 12] ; and the skull of 

 L a g o p u s 1 e u c u r u s , and P e d i o c a e t e s p . c o 1 u m - 

 b i a n u s ; the pelvis of C a n a c h i t e s canadensis; and 

 the trunk skeleton of L a g' o p u s 1 e u c u r u s [pi. 13] . 



I did not think it necessary to reproduce any of these figures in 

 the present connection, as the former memoir is quite accessible — 

 a copy being in nearly all the large libraries of the world, and in 

 the personal libraries of many comparative anatomists. 



Since that memoir and the present treatise were written, however, 

 I have examined the skeletons of not a few species of the Gallinae 

 from several parts of the world, and from these I have selected 

 various parts of the skeleton, figures of which are given in my 

 • plates herewith presented, for comparison with what has been 

 brought out in my earlier studies of the osteology of this group 

 of birds. These figures, as far as possible, illustrate the osteology 

 of some of the principal families of the Gallinae. as the Cracidae 

 (C r a X g 1 o b i c e r a) ; the Tetraonidae ( Bonasa and others) ; the 

 Phasianidae (Phasianus and others) ; the Aleleagridae (Aleleagris) : 

 and a variety of other genera from other families, as will be appre- 

 ciated by referring to my plates. 



It is interesting to note the form of the sternum, and the bones 

 of the shoulder girdle in Crax globicera [pi. 5, fig. 22]. 

 The carina is very deep and of a triangular outline with a large 

 pneumatic foramen at the upper part of its anterior border. A large 

 group of pneumatic foramen is also found at the forepart of the 

 dorsal aspect of the body of the sternum, and a big single median 

 one over the base of the largely developed manubrium on the same 

 aspect of the bone. They also completely riddle the spaces between 

 the facets for the costal ribs, and smaller ones in the coracoidal 

 grooves. The peculiar form of the xiphoidal processes is well 

 shown in the figure of the plate ; they remind us of these prolonga- 

 tions in some of the pigeons. 



