272 



spur. There are 20 vertebrae between the skull and the sacrum, the last six of which bear 

 moveable ribs : of these the first two pairs are free, the rest are joined by haemapophyses to 

 the sternum ; the last (seventh) pair of ribs are attached to the sacrum. There are 6 caudal 

 vertebrae. 



Mus. South. 



1413. The skull of the Common Fowl. Hunterian. 



1414. The skull of a variety of the Common Fowl (Gattus domcsticus), having a 

 spherical bony cyst above the orbits. 



Whether this peculiarity of the skull should properly constitute a variety is uncertain, 

 being apparently the result of disease alone : the latter opinion is supported by the authority 

 of Pallas. 



Hunterian. 

 Genus Phasianus. 



1415. The skull of the Silver Pheasant (Phasianus nycthemerus}. Hunterian. 



Genus Tetrao. 



1416. The skeleton of the Capercailzie, or Cock of the Woods (Tetrao urogallus). 



This is chiefly remarkable for the prolongation of the angle of the jaw upwards and back- 

 wards. The mastoid process coalesces with the postfrontal. The spines of the last five 

 dorsal vertebrae have coalesced into a continuous osseous ridge, and the centrum of the last 

 dorsal alone remains free ; the rest form a continuous crest of bone, sending down deep pro- 

 cesses from each, the ends of the first three being blended together. The scapula is of 

 unusual length, reaching to the ilium. The apex of the furculum is much prolonged and 

 expanded. Both the episternal and costal processes of the sternum are produced. The cal- 

 caneal ossicle which plays upon the back part of the tibial trochlea is preserved in both legs. 

 The distal rudiment of the innermost metatarsal supports, as usual, the short back-toe. 

 There are 20 vertebrse between the skull and sacrum, of which the last six support ribs : of 

 these the first two pairs are free ; the four succeeding ones articulate with the sternum by 

 bony haemapophyses ; the last (seventh) rib is attached to the sacrum, but does not reach 

 the sternum. There are 6 caudal vertebrse. 



s. South. 



1417. The hyoidean arch of the Capercailzie (Tetrao urogallus). 



Presented by Dr. Leach, F.L.S. 



1418. The skeleton of the Ptarmigan (Tetrao Layopus). 



The four dorsal vertebrae in advance of the last are anchylosed together, of which the cen- 

 trums are compressed, and indicated chiefly by their long hypapophyses, which also coalesce 



