.1837.] 



On two neto Genera of Rasorial Birds. 



301 



straight, rounded. Legs and feet rather small. Tarsi plumed below 

 the blunt small spurs. Acrotarsus reticulo-scutellate. Lateral fore 

 toes subequal ; hind perfect ; the fores pectinated to the sides. 



Habitat — The Himalayan region, in the immediate vicinity of the 

 perpetual snow. Habits, gregarious in coveys ; never perches ; feeds 

 on aromatic buds and leaves, on roots, insects and seeds. Trachaea sim- 

 ple. Intestines and creca approaching the length in the grouse.* 



Type, Perdix Lerwa nobis. Proceedings of the Zool. Society of Lon- 

 don, September 1833. Lerwa Nivicola nobis. Affinity equal with 

 Perdix and with Tetrao, leading from the one to the other. 



Structure and size. 15 inches long by 24 in expanse of wings; bill 

 •j-f- ; tail 5; tarsus less 2; central toe \t&\ hind T V; weight l|to II lbs. 

 Bill to head as 15 to 22, very stout, hard and uncompressed : maxilla 

 not much rounded on the culm en, but spreading on the sides, and so 

 much longer and larger than the mandibula as nearly to conceal it. 

 Tomiai somewhat scarpt and trenchant. Nares small, opened vertically 

 towards the head, closed in front and above by a tumid hard arched 

 scale which is quite nude, though the thick set plumes at the base of 

 the bill pass forward, under the scale, to the anteal point of the nostrils,, 

 Tongue somewhat fleshy, triangular, pointed and entire. Intestines 4 

 feet long, with creca of ten inches each. Gizzard large, strong and 

 dark-hued, I to | of an inch thick. Bottom of aBSophagus dilated and 

 glandular, but very remote from a galline crop. Head and orbits com- 

 pletely clad ; plumage of,the body very full, strong and composed; the 

 shafts of the feathers, very strong towards their bases, and rather sud- 

 denly attenuated, particularly on the croup, whence results that peculi- 

 arity which is so noticeable in Cebbepyrine Shrikes. A small portion 

 of the web of each feather, next the shaft, is very strong ; but beyond 

 that limit, the web passes suddenly into very soft down ; and beneath 

 each principal plume is a smaller one composed almost wholly of down.f 

 This relates to the interior of the plumage : for, exteriorly, it is com- 

 posed and of ordinary structure; only somewhat elongated and nar- 

 rowed, but without lanceolation, on the flanks. 



The wings extend considerably beyond the base of the tail, or, usual- 

 ly, to about three inches from its tip. They are very firm, unbowed, 

 and void of gradation in the prime quills, the 4 first of which are nearly 

 of equal length, commonly exceeding the tertials by about \ an inch. 



* Cervical vertebrae 13. Dorsal, 7. Superior processes of the spinal column large, \ inch 

 and more high. 3 false ribs. Scapula strong and flat. Cavity of the sternum, or chest and 

 abdomen, very capacious, being 3 inches in depth, and 2 in Width. Sternal crest or keel, 

 moderate ; and the sternum not much produced over the belly. 



% The peculiarity adverted to is not proper to our Lerwa alone, but is by no means so 

 conspicuous in other allied birds. 



