290 THE ANATOMY OF VERTEBRATED ANIMALS. 



side of tlie sliovilder-joiiit in most CoracomorphcB and 

 CeZeomorj^/iCE. 



In the Carinatoe, the glenoidal end of the scapnla is 

 divided into two portions; a, glenoidal process, which expands 

 to form the upper part of the glenoidal cavity, and to unite 

 with the coracoid — and an acromial process, which gives 

 attachment to the outer end of the clavicle. The glenoidal 

 end of the coracoid is in like manner divided into two por- 

 tions; a glenoidal process, which unites with the scapula, and 

 a clavicular process, which ai-ticiilates with the outer surface 

 (^f the clavicle, near its outer end. 



The clavicialar process of tlie coracoid probably represents 

 the procoracoid of Lacertilia. In the Batitce there is no 

 distinct clavicular process, but the anterior part of the 

 coracoid, near the glenoid cavity, may be produced and 

 separated by a notch, or fontanelle, from the rest, as a 

 lacertiHan procoracoid. There is no trace of clavicles in 

 the Apteryx and in some Parrots. In the Emeu, and in 

 sundry Carinatce (some Pan-ots and Owls), the clavicles 

 remain distinct from one another, or connected only by 

 fibrous tissvie; but, in the majority of birds, they are very 

 early ankylosed together, and with the representative of 

 the interclavicle, in the middle line, into a single bone, the 

 furculwm, the strength of which bears a pretty close re- 

 lation to the exertion required of the wings in flight, or 

 in natation. In the passerine birds the scapiilar end of 

 the clavicle is visually expanded, and ossifies separately, 

 as an epicleidium. A median process fhypocleidiumj is 

 frequently developed from the interclavicular part of the 

 furculum, and this may be united with the carina of the 

 sternum by strong fibrous tissue, or even by continiious 

 ossification. In Opisiliocomus, the furculum is ankylosed 

 with the manubrial part of the sterniim, on the one hand, 

 and with the coracoids on the other. Ankylosis of the fur- 

 ciilum with the coracoids has also been observed in JDidus. 



The fore limb of a bird, when in a state of rest, exhibits a 

 great change of position if it be compared with that of an 

 ordinary reptile ; and this change is of a character similar to, 



