SKELETON 



857 



Bubo ignavus. 



Clav. 



CORVDS CORAX. 



Coracoid, in the Ostrich alone of Birds. Tiiis prsecoracoidal pro- 

 cess is of some taxonomic value,^ and near its base is either a notch 

 or a small foramen for the passage of the nervus supracoracoideus 

 which supplies the muscle of the same name, and indicates the 

 boundary between Coracoid and Prsecoracoid. A strong ligament, 

 sometimes partly ^^,„ 



ossified, frequently 



extends along the ^ ^ ^Acd. 



inner margin of both 

 coracoid and prse- 

 coracoid to the ros- 

 trum of the sternum. 

 In most Birds the 

 riirht and left Cora- 

 coids do not touch 

 each other, but in 

 some groups they 

 meet, as in certain 

 Tubinares, Cathar- 

 tidx, some Falcon- 

 idce, Larldx, Opistho- 

 cornus, some Gallhm, Bucerotidx, Upupa and Tnxjonidx, while in some 

 other groups one overlaps the other, the right lying ventrally upon 

 the left, as Dromaius, Icldhyornis, Apatornis, certain Tulmmres, some 

 Steganopodes, Ardeidx and Ciconix, Fhrnnicopterus, some FalconidcC, 

 some Gallinx, Musophaga, Striges and Mcropidx. From the distal 

 third part of the lateral margin of the Coracoid a long process often 

 projects, overlapping the neighbouring part of the anterior margin 

 of the sternum, examples of which may be especially seen in 

 Tiibiiictres and Pici. 



The Scapula or shoulder-blade is more or less sabre-shaped, 

 usually ending in a point, but its extremity being much curved in 

 the Fici. It extends backward from the humeral joint over the ribs, 

 lying almost parallel to the vertebral colunni. The median anterior 

 knob is the acromion. In the Fuititai and Didus the Scapular and 

 Coracoid are fused, which might be regarded as correlative with 

 the loss of flight, were it not that the same fusion is observable in 



(Inner view.) 



Acd. Acrocoracoid ; Acm. Acromium ; Clav. Clavicle ; 



I\ rnrcoracoid process ; ."^r. Scapula. 



^ It approaches the Acrocoracoidal process in Cnemiornis, Falco, Asio, Merops, 

 Irrisor and Cuculus ; fusing witli it and forming a complete osseous bridge across 

 the supracoracoid sulcus, in Musophaga, Corythaix, Merops, Upupa, Buceros and 

 Alccdo ; while in Didus and Opisthocomus it fuses with the Clavicle, of which in 

 Hesperornis it is the sole support. In Dromszus and Casuarius it is small and 

 bears the clavicular remnant. It varies much in size and, as above stated, is 

 complete in Struthio only. It is large, though without meeting the Clavicle, in 

 Ichthyornis, Sula, Grus, Trichoglossus and others ; but very small or absent in 

 Aptcryx, Tinavuis, Steganopodes, Gallinae and Passeres. 



