334 BULLETIN UNITED STATES GEOLOGICAL SURVEY. [VolYI. 



form one broad process placed transversely with a mesial keel in front 

 as the only indication of its original device. 



The carotid canal seems to commence and terminate in the same ver- 

 tebriTB both in Tetraoninw and Odontophorince, 



Of the eminently characteristic dorsal bone little has to be said in 

 addition to what has already been noted above. The number of vertebrae 

 included in the anchylosis is never more nor less than four, and the 

 first vertebral ribs have no hfemapophyses; so they never connect with 

 the sternum, though they invariably bear uncinate processes, and in many 

 species contribute a good share toward the stability of the thoracic 

 parietes. The metapophysial i^rocesses vary principally in their ex- 

 tent: in Bonasa, Cupidonia, and Pedicecefes. In several specimens they 

 nearly cover the tops of the diapophysial arms. In Lagopus a narrow 

 bar defines them, connecting the extremities of the transverse processes 

 with comparatively few offshoots. In Tetrao canadensis the bone is very 

 long and delicate. In T. ohscurus it has the same general appearance as 

 in Centroccrcus. The hypapophyses develop after the common type, but 

 often irregularly; they are found to be missing on the ultimate segment 

 or rather the pelvic end of the bone in the Quails. 



The free and last dorsal may or may not have a hypapophysis; we be- 

 lieve it never does in the Odontopliorinw. It is overlapped by the ilia in 

 Cnpidonia and the Sharp-tailed Grouse. We find this to be a very marked 

 feature in the last, and well marked among some of these birds sent me 

 by Capt. James (J. Merrill, Medical Department Uuited States Army, 

 from Fort Ouster, Mont., at a time thej' were particularly acceptable, and 

 when this erratic fowl became suddenly and unusually rare in many 

 localities, so that the gift was reckoned at the time as more than val- 

 uable desiderata. As fitr as the sacral vertebrro aie concerned, the same 

 general plan seems to be carried out : sixteen seems to be the allotted 

 number among the Grouse and, as a rule, among the Partridges. In 

 these birds the sacrum, i. e., the anchylosed sacral vertebrte, is much 

 narrower, as is the entire i^elvis, and much fewer perforations are to be 

 seen among the dilated processes that go to meet the ossa innominata. 



In Cupidonia and Pedmcefes the sacrum is very broad, conforming to 

 a pelvis in these birds that will be described further on. We find in a 

 specimen of Tetrao canadensis, for which we are greatly indebted to Mr. 

 Manly Hardy, of Brewer, Me., where thesacroiliac anchylosis is so per- 

 fect, and original land-marks so obscure, that one might easily imagine 

 the i)elvis in this individual as being developed from a very much fewer 

 number of ossific centres. The caudal vertebrte number five in all the 

 Grouse except Cupidonia and Pedicecetes, these birds each having dis- 

 tinctly si,r apiece. We would especially call the reader's attention to this 

 fact, because when we come to discuss the pelves of these two birds, and 

 recapitulate general skeletal data, it will be found that, as far as osteo- 

 logical simularities are concerned, they come very near to each other. 

 The coccygeal vertebras, otherwise, in common with the i^ygostyle, show 



