BY W. J. S. McKAY. 335 



portion of the latissimus as part of the pannicuhis, i.e., M. dermo- 

 fiexor antebrachii. 



]\I. RHOMHOIDKUS. 

 KcniDNA et Ornithorhynchcjs: M. rhomhoidtu><, all authors. 



Echidna. 



Origin. The I'homboid is imperfectly divided into anterior 

 and posterior portions. The anterior and larger portion arises by 

 an aponeurotic tendon from the linea temporalis on the parietal 

 bone, and fiom the median raphe as far back as the 5th cervical 

 vertebra. 



Insertion. The muscle runs outwards and posterior under 

 cover of the trapezius, and is inserted along the anterior three- 

 fourths of the vertebral margin of the scapula. 



Origin. {a) Posterior portion. — This part, imperfectly 

 differentiated from the anterior, is represented by a narrow band 

 of muscular fibres arising from the median raphe (in intimate 

 connection with its fellows of the opposite side) in the region of 

 the 5th and 6th cervical spines. 



Insertion. Running upwards and outwards it is inserted 

 on the inner margin of the posterior portion of the vertebral 

 border of the scapula ; being placed between the anterior part of 

 the rhomboid and the insertion of the costal portion of the serratus 

 magnus. 



Relations. Tlie anterior rliomboid at its origin lies under 

 cover of the trapezius, and has a similar thin aponeurotic tendon 

 of origin. As it luns posteriorly it becomes fleshy and a thick 

 sheet of mu.scle is developed which is continued to its insertion ; 

 tendinous fibres being developed only at the junction cf the 

 insertion of the anterior and posterior parts. From the manner 

 in which the posterior portion is connected with its fellow of the 

 opposite side, this part strongly resembles the transverse cervical 

 muscle of some animals. 



