Strigidje.] 



OSTEOLOGIA AVIUM. 



[Strigin^. 



Ulna and radius also weak. Metacarpals widely divided ; the posterior or smaller one 

 broad at its proximal extremity, and much flattened for its whole length. 



Femur with the trochanters moderately developed ; distal extremity much enlarged ; 

 shaft nearly round ; tibia triangular at its upper extremity, and rounded downwards. 



Metatarsus much hollowed out posteriorly ; calcaneal process highly developed, blunt 

 at the extremity, and continued in the form of an edged keel a short distance down the 

 entometatarsal bone ; anteriorly very deeply hollowed out on the inside of its proximal 

 extremity between the ento- and mesometatarsal bones, the former of which is provided 

 with a strong curved bony sheath, extending across the cavity through the extensor 

 tendons of the foot pass. 



Measurements. 



Tenths. 



Length of humerus 61 



Length of ulna 71 



Length of radius 67 



Length of metacarpus 33 



Length of femur ....... 37 



Length of tibia 48 



Length of metatarsus ..... 22 



Length of sternum 49 



Tenths. 

 Breadth of posterior margin of sternum 22 

 Breadth of anterior margin of sternum 20 



Depth of keel 10 



Length of head . . 35 



Breadth of head 26 



Length of pelvis 43 



Breadth of pelvis 20 



Illustrations. 



Metatarsi, Plate II. fig. 7. 

 Palatine bones, Plate VI. f 



;. 10. 



Coracoid, scapula, and furculum, Plate VII. 



fig. 3. 

 Posterior margin of sternum, Plate IV. fig. 2. 



Strix, Linn. 



Flammea, Linn. 



Cranium similar to Nyctea nivea ; interarticular bones bent backwards in the centre 

 where articulated with the sphenoid. 



Sternum with a rounded indentation on each side of the keel, very short, slightly 

 convex ; keel very shallow. No manubrial process. 



Metatarsi similar to Nyetea^ but longer in proportion to the tibia. 



Hinder metacarpal bone not arched, except at its proximal extremity. 



Measurements. 



Tenths. 

 Length of humerus 32 



Length of ulna 37 



Length of radius 35^ 



Length of metacarpus 15 



Tenths. 

 Length of femur 19 



Length of tibia 35 



Length of metatarsus . . . . . 25 



Length of sternum . . . . . . 15 



e2 27 



