MUSCLES OF THE FORE LIMB 81 



organ, forming a leva-tor in-fjluviei. A portion of the cucullaris 

 also directs itself towards the patagium, and in most Passeres 

 and in parrots, Pici, and Upnpa forms a special cucullaris 

 propatagialis, joining the tensor longus tendon. The pars 

 cervicalis of the cucullaris arises from the dorsal edge of the 

 neck, and is inserted near or in common with the other part. 

 In many birds (e.g. Anseres) a slip is given off from this 

 which supplies the humeral pterylon. It is termed the cucul- 

 laris dorso-cutaneus. 



Rliomboideus Externus. This muscle arises tendinously, 

 the width of the tendinous part being about the same as 

 that of the muscular part, from the last cervical and from 

 the dorsal vertebra ; it is inserted fleshily along the whole 

 length of the scapula. The muscle varies but slightly ; the 

 origin is more or less extensive, and the vertebra from 

 which it arises are not always the same. Its insertion is 

 not always limited to the scapula, but sometimes extends on 

 to the furcula. In Casuarius and Apterijx the muscle arises 

 from the ribs. 



Elioniboideus Profundus. This muscle also arises ten- 

 dinously from the neural spines of the dorsal vertebrae, or 

 from both dorsal and cervical. Its origin sometimes extends 

 as far back as to the ilium. It is inserted into the 

 scapula below the last. In Casuarius and Apteryx this 

 muscle arises from the ribs. The rhomboideus profundus is 

 occasionally divided into two distinct parts ; in Megalama 

 there are three distinct divisions. 



Serratus Super ficialis. This muscle is divided by FUB- 

 BRIXGER into three parts, of which two are always present, 

 while the third is sometimes absent. This is the -pars 

 metapatagialis. The pars anterior arises from one or more 

 ribs on the boundary line between the cervical and dorsal series. 

 It is attached to the scapula along the ventral border, but, quite 

 exceptionally, in Bliea on to the dorsal border. The pars 

 posterior springs from a varying number of dorsal ribs, and 

 in several birds (e.g. Rliampliastos) it, with the pars anterior, 

 which can hardly be separated as a distinct muscle, springs 

 from a considerable number of ribs five in the case referred to. 



