TETRAONIDiE.] OSTEOLOGIA AVIUM. [TETRAONINiE. 



Leg-bones. The tibia very long ; metatarsus very short ; calcineal ridge very deep at 

 the upper end, and gradually tapering off to a short spur at the junction of the 

 accessory metatarsal bone, which is not twisted over the flexor tendons as among the 

 pigeons. 



Measurements. 



Tenths. Tenths. 



Length of humerus 20J 



Length of ulna ....... 24 



Length of metacarpus 12 



Length of femur ...... 13 



Length of tibia 23 



Length of metatarsus 9 J 



Length of sternum 31 



Breadth of posterior margin of sternum 10 

 Breadth of anterior margin of sternum 10 



Depth of keel . 12* 



Length of head 20 



Breadth of head 9± 



Length of pelvis 30 



Breadth of pelvis 15 



Pterocles, Temm. 



Quadricinctus, Temm. 



My specimen of this bird is a young one, but is without the foramina in the pelvis 

 between the ilium and sacral vertebrae ; has the spur on the metatarsus articulated to a 

 calcineal bone, situated about the same height up the metatarsus as the spur is in 

 P. arenarius ; and the posterior margin of the sternum is without foramina. 



Pterocles, Temm. 



Alchata, Linn. 

 Similar to the foregoing, but with the foramina on the upper surface of the pelvis, 

 as in P. arenarius. Metatarsal spur articulated to a very small flat calcineal bone. 

 Sternum with two foramina on its hinder margin. 



Syrrhaptes, III. 



Paradoxus, III. 

 Similar to the foregoing, but without the metatarsal spur. 



Tetrao, Linn. 



Urogallus, Linn. 

 Cranium. My specimen is that of a female. Cranium much elongated behind the 

 orbits; occipital crest and protuberance well marked, the latter with a deep inden- 

 tation on each side ; a deep indentation extending over the vertex. Palatine bones 

 consist of narrow strips of bone flattened perpendicularly, and very slightly wider 

 towards their hinder ends. Orbital septum with two small foramina, the upper one 

 somewhat elongated, the lower one rounded; the ethmoid bone appears in the shape of 

 162 



