May 31, 1831. 

 N. A. Vigors, Esq. in the Chair. 



At the request of the Cliairman, Mr. Gould exhibitecl a specimen 

 ofthe malė of the UrogaUus medius ; tlie Tetrao hybridics of Gmeliii 

 and Dr. Latham, and the Tetrao medius of M. Temminck. 



Mr. Yarrell observed that this individual, with one other example of 

 the sanie rare species, also a malė, was found among a considerable 

 number of the Tetrao UrogaUus of both sexes, brought from Nor- 

 way by a hoat partly laden with lobsters for the London market. 

 Some of the older writers considered this bird to be a hybrid pro- 

 duced betvveen the Wood Grouse and the Blach Grotise, and had 

 named it accordingly : modern authors have, however, established 

 its distinction as a species ; and the female and its egg are now' 

 known. Notwithstanding the general resemblance betvveen these 

 two large Wood Grouse they are decidedly and very obviously dif- 

 ferent. In the Tetrao medius the beak is black ; the shining fea- 

 thers on the front ofthe neck and breast are of a rich Orleans-plum- 

 colour ; and of the 18 feathers of the tail the outer ones are the 

 longest. In the Cock of the JVood the beak is white ; the feathers 

 on the front of the breast are of a dark glossy green ; and the centre 

 feathers of the tail are the longest. 



The organ of voice in the Tetr. medius is peculiar. The trackea 

 of this bird and that of the Tetr. UrogaUus vvere exhibited ; and Mr. 

 Yarrell pointed out that the trachea of the Tetr. medius, eleven 

 inches in length, has no loose fold, likę that of the Tetr. UrogaUus, 

 but descends in a straight line to thelungs. From the thyroid car- 

 tilage two pairs of museles follow the course of the trachea, one pair 

 firmly attached to the trachea itself, the second pair suspended 

 loosely in the cellular tissue. Both these pairs of museles, after an 

 extent of eight inches, are lošt in a membranous expansion, form- 

 ing a sheath, which invests the inferior fourth portion of the trachea, 

 and from which sheath one musele only on each side is sent ofF, 

 immediately above the bifurcation of the bronchice, to be attached 

 to the inner surface ofthe sternum. 



The stomach is a true gizzard of great muscular power, and the 

 intestines and Cčeca, as in all the Grouse tribe, are very long : the 

 cceca in the present instance measured each three feet in length. 



There is reason to believe that this bird inhabits the Apennines 

 as well as the more northern localities assigned to it. Mr. Fox in 

 his ' Synopsis ofthe Nevvcastle Museum' quotes a note ofthe late 

 Mr. Tunstall vvhich statės that " he knew some old Scotch gentle- 

 men who sąid they remembered, that when young, there were in 

 Scotland both the Coch ofthe Wood, and the Tetr. hybridus." 



Mr. Yarrell availed himself of the opportunity to statė that the 

 hybrid Grouse of White's ' Natūrai History of Selborne' is believed 



[No.VII.] ZooL. Soc. Proceedings of the Comm. of Science. 



