CoRVIDiE.] OSTEOLOGIA AVIUM. [CoRVINiE. 



Corvus, Linn. 



Frugilegus, Linn. 



Very similar to Corone, but has the dorsal processes of the vertebrae less marked ; 

 only one foramen in the orbital septum, and the foramina on the posterior margin of 

 the sternum nearly closed at their hinder extremities by the expansion of the lateral 

 splints. 



Corvus, Linn. 



Monedula, Linn. 



Skeleton altogether much slighter than in the other species of the genus Corvus 

 mentioned. 



Cranium. The orbital septum with two foramina. 



Sternum with the posterior foramina very open, the lateral splints not reaching the 

 posterior margin. 



Pica, Briss. 



Candata, Ray. 



Very similar to Corvus, but with the four vertebra? next the atlas only having dorsal 

 spines ; lateral splints on the posterior margin of the sternum expanded at their 

 extremities, partly closing the fissures, which are deeper than in Corvus, and not so 

 rounded at their anterior end. 



Pelvis without the third foramen anterior to the obturator, which, as well as the 

 obturator, is large. Manubrial process very small ; scapula more recurved than in 

 Corvus. 



Measurements. 



Tenths. 



Length of humerus ..... 1 9 

 Length of ulna . . . . . . .18 



Length of metacarpus 11 



Length of femur 16 



Length of tibia 29 



Length of metatarsus ..... 21 



Length of sternum ...... 17 



Tenths. 



Breadth of posterior margin of sternum 11 J 

 Breadth of anterior margin of sternum 9 



Depth of keel 5 



Length of head ........ 27 



Breadth of head. 12 



Length of pelvis ...... 18 



Breadth of pelvis 13 



Nucifraga, Briss. 



Caryocatactes, Linn. 



Cranium with the mandibles rather straighter than in Corvus, the upper one extend- 

 ing forwards in a nearly straight line beyond the lower, and only very slightly bent 

 downwards at the tip ; orbital septum with two small foramina. 



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