MOTACILLIDJE.] OSTEOLOGIA AVIUM. [MoTACILLINJL. 



Melanocorypha, Boie. 

 Tartarica, Pall. 



Cranium with orbital septum entire. 



Sternum similar to Otocoris, but with the manubrial process much longer ; the ante- 

 rior lateral edge of the sternum to which the ribs are articulated, very much produced. 

 Remainder of the skeleton similar to Alauda. 



Measurements. 



Tenths. 



Length of humerus 11 



Length of ulna 15 



Length of metacarpus .... 7 



Length of femur 9J 



Length of tibia 14 J 



Length of metatarsus . „ . . 11 



Length of sternum 12 



Tenths. 



Breadth of posterior margin of sternum 8 J 



Breadth of anterior margin of sternum 5 J 



Depth of keel 4 



Length of head . 16J 



Breadth of head 7 J 



Length of pelvis ...... 13 J 



Breadth of pelvis 8 



Motacilla, Linn. 



Alba, Linn. 



Cranium rounded, a slight channel proceeding from the nasal channel to the vertex ; 

 occipital ridge and protuberance not very distinct ; orbits, and space between them, of 

 moderate size; septum with two fissures. Palatine bones truncate where they join the 

 sphenoid, to which they are anchylored, the outer edges slightly deflexed ; interarticular 

 bones slightly bent. 



Sternum large, the central portion broad, with two posterior (not very deep) fissures, 

 the bony rib bounding them triangular at the tip ; keel very deep in proportion to the 

 length of the sternum, the point carried as far forward as the end of the manubrial pro- 

 cess, scolloped out in front, rounded below ; manubrial process long, turned slightly 

 upwards. 



Pelvis similar to Alauda, but much broader in proportion to the size of the bird ; 

 the anterior portion of the iliac bones in particular ; ischiadic foramen small ; obturator 

 of moderate size. 



Ribs of moderate strength ; styliform process of nearly equal size throughout. 



Furculum very much arched in front ; the upper extremities of the rami long, divari- 

 cating more than in Alauda, the process at their junction flattened and large, turned 

 backwards. 



Coracoids rather long, bent a little outwards at their upper extremities. 



Scapula longer than the humerus, slightly widened at the point from which it is 

 sloped off to the tip. 

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