336 SHOULDER-GIRDLK IN MONOTEEMES, 



Ornithorhy>'chus. 

 Origin. The rhomboid may likewise be divided into anterior 

 and posterior parts. The anterior j)ortion ai-ises from a curved 

 depression on the parietal bone immediately postero-external to 

 the depression from which the trapezius takes origin ; and from 

 the median raphe (lig. nuchse, Meckel) common to this muscle and 

 the anterior part of the trapezius, and which is attached to the 

 mid point of the occipital crest : the posterior limit of this cervical 

 origin reaching to about the spine of the 4th cervical vertebra. 

 Tlie posterior portion is represented by a narrow fasciculus 

 differentiated from the anterior part, and which arises from the 

 median raphe in the region of the 5th cervical spine. 



Insertion. The fibres of the anterior part of the muscle 

 run outwards and posterior, while the posterior fibres run out- 

 wards and somewhat forward, the whole muscle being inserted on 

 the posterior half of the vertebral border of the scapula (with the 

 exception of a small area close to the distal extremity of this 

 border occupied by the costal serratus and slip to the latissimus). 

 Relations. The rhomboid is hidden anteriorly })y the 

 anterior part of the trapezius. Its insertion is related to the teres 

 major externally, costal serratus posteriorly, and cervical portion 

 of the serratus internally, while anteriorly is the acromio- 

 trachelien. 



Innervation. Echidna : ii., iii., cervical nerves. Oryii- 

 thorhynchus : iii., cervical nerve. 

 Westling : same as above. 



Echidna. 

 Westling de£>cribes the origin from the parietal bone and the 

 dorsal middle line of the neck, and the insertion into the greater 

 part of the vertebral border of the scapula parallel to the insertion 

 of the posterior portion of the trapezius. The nerve supply from 

 ii. and iii. cervical nerves. 

 Leche follows Westling. 



MiVART describes the origin from the occiput and mid-line of 

 the back of the neck, and the insertion as Westling does. 



