78 



THE GENERAL ANATOMY OF THE LEMUROIDEA [SECT. A 



along its upper margin. A tendinous strand is seen among 

 the fibres of insertion 1 . 



3. The sternomastoid muscle has thin ribbon-like sternal 

 and clavicular heads. These stand in contrast to their massive 

 counterparts in Man, and seem to subserve another function, 

 probably in relation to the difference in attitude. The Xlth 

 cranial nerve pierces the muscle, which is a wide sheet near its 

 occipital insertion. It blends with the M. trapezius, and even 



M.aurlab.sup. 



M.lev. lab. sup 



Fig. 42. Cutaneous musculature of the head of Lemur mongoz to shew some 

 of the more definite constituents of the muscular sheet. (From a specimen in the 

 Cambridge Anatomy School.) 



encroaches on the ligamentum nuchae. The M. trapezius thus 

 fails to obtain an attachment to the occiput, unless this be 

 represented by the occipito-scapular slip of muscle seen on the 

 surface of the M. trapezius. The latter is reinforced by an 

 extensive " rhomboid " sheet on its deep aspect. 



4. The shoulder-muscles include the powerful M. deltoideus, 

 which arises from the whole length of the scapular spine (lower 

 margin), and at its insertion shares the external lip of the bicipital 

 groove with the M. pectoralis major. The latter muscle has no 



1 For the form of the M. digastricus in Macropus, etc., cf. Toldt, Sitz. der k. k. 

 Akad. der Wissen. zu Wien, Band cxvu. Abt. m. Math. Nat. Kl. 1908. 



