the Wombat and Tasmanian Devil. 161 



dons, a division into coraco-radial and gleno-ulnar portions 

 can be made without dilSiculty. In Macrojyus giganteus the 

 portions are distinct, and the gleno-ulnar muscle unites at 

 its insertion, as described by Prof. Owen, with the brachialis 

 anticus ; the same occurs in Macropus Bennettu\ in the 

 Phalanger, and in the Opossum, in all of which the coraco- 

 radial muscle is nearly double the size of the gleno-ulnar. 

 Mr. Galton mentions that one individual of Macropus 

 Bennettii had only a single head to its biceps ; but this is, 

 I think, an individual variety, as the four individuals of 

 this group dissected in Dublin had two heads : but even in 

 this case the duality of the muscle is shown by its double 

 (radial and ulnar) insertion. Meckel describes the insertion of 

 the gleno-ulnar muscle as separate from that of the brachialis 

 anticus. In the specimen which I examined they were scarcely 

 separable. The connexion between the tendons in Sarco- 

 philus might at first sight have led to their having been 

 considered but one head ; however, a closer examination at 

 once decided the duality of the origin. This union is interest- 

 ing as bearing upon the important point suggested by Prof. 

 Humphry, that, as the portion of the glenoid cavity from 

 which the long head of the biceps arises is in reality coracoidal, 

 so both heads of this muscle are truly coracoidean in their 

 origin. Professor Owen (Anatomy of Vertebrates, vol. iii. 

 p. 12) states that in Perameles the coracoidal head is suppressed, 

 and also that the fleshy belly is inserted along with the bra- 

 chialis internus into the ulna, while another portion seeks the 

 radius — thus showing that, while the origin is single, the 

 muscle in reality is double. Meckel only found one head for 

 this muscle in Macropus giganteus. 



The brachialis anticus in the Wombat was as usual in its 

 position and attachments, winding round the bone below and 

 external to the deltoid-crest, lying in a deeply excavated sul- 

 cus in the humerus ; its insertion is behind the attachment of 

 the gleno-ulnar muscle, and quite separate from it. Its posi- 

 tion is similar in SarcojyMlus, the Bandicoot, Opossum, Pha- 

 langer, Bennett's and Giant Kangaroo. 



The triceps longus is large, and occupies more than a third 

 of the axillary margin of the scapula. It is equally well 

 developed in the Tasmanian Devil, the Wallaby, the Giant 

 Kangaroo, the Opossum, Bandicoot, and Phalanger, 



The lateral heads are united into one large humeral muscle, 

 inseparable from each other, and with the usual course and 

 attachments, in all the marsupials. The dorsi epitrochlear in 

 all is quite separate from the true triceps, and seeks its usual 

 insertion into the inner side of the olecranon. The relation of 



