316 SHOULDER-GIRDLE IN MONOTREMES, 



Leche follows Coues, and accordingly describes the teres as 

 divided into two parts. 



Meckel also describes two muscles, a " superficialis posterior, 

 longior, sed angustior, a marginis superioris scapulae parte pos- 

 teriore ortus," and "alter ab eo tectus, a dimidio posteriore 

 scapulEe superficiei externa? ortus," etc., this being part of the 

 subscapularis. 



CuviER and Laurillard figure this muscle single, as the "grand 

 rond (scapulo-humerien)," PI. 266, fig. 1 ; and on PI. 268, fig. 4. 

 the subscapularis and teres are so clearly shown that it is evident 

 that they did not mistake the subscapularis for part of the teres 

 major. 



M. teres minor. 



Echidna : Terefs minor, Fewkes ; Suh^icapularis acctssorim, Westling, 

 Leche ; described hy Mivart, hut not riamed. 

 Ornithorhynchus : Suhscapidaris, Coues. 



Echidna. 



Origin. The teres minor arises on the external face of the 

 scapula from a slight ridge which runs from the dorso-anterior 

 border of the glenoid cavity u])wards and posteriorly to meet the 

 glenoid ridge. 



Insertion. The origin is tendinous, and the muscle running 

 ventrally and posteriorly over that part of the external face of the 

 scapula adjoining (dorsal to) the glenoid cavity, lies on the capsu- 

 lar ligament, and then passes inwards to be inserted on that part 

 of the posterior face of the humerus situated between the proximal 

 (ventral) extremity of the supinator ridge and the lesser tuberosity. 



Relations. At its origin the muscle is hidden from view 

 by the infraspinatus, and it arises between this latter muscle 

 anteriorly and the long head of the triceps posteriorly. 

 At its insertion the origin of the internal head of the triceps 

 bounds it distally, while proximally and internally is the insertion 

 of the subscapularis. 



