the Wombat and Tasmanian Devil. 157 



and upper five ribs to the ])cctoral ridge of the humerus, 

 and is undivided. The muscle is large and single likewise in 

 the Giant Kangaroo (Meckel describes it as bilaminar) and in 

 Bennett's Kangaroo. The Opossum and Phalanger displayed 

 no sign of segmentation. 



The pectoralis minor of the Wombat is a small thin muscle 

 which lies beneath the last named and inferior to the second 

 slip of the greater pectoral just referred to ; it arises from the 

 mesosternum, and is inserted into the outer part of the greater 

 tuberosity of the humerus, the coraco-humeral ligament, and 

 into the coracoid process. In Sarcop/n'Ius it is attached to 

 the head of the humerus and the shoulder-capsule, and, more 

 slightly than in the Wombat, to the coracoid process ; and in 

 this animal its origin is from the abdominal linea alba, lower 

 ribs, and mesosternum. This muscle is joined to the greater 

 pectoral as a deep inseparable lamina in the Giant Kangaroo 

 and in Macropus Bennettii^ or absent, according to Meckel 

 and Prof. Haughton (Proc. R. I. A. 1866, p. 81). In the 

 Phalanger and Opossum it is present and passes to the humeral 

 head below the shoulder-capsule ; it is similarly situated in 

 the Bandicoot. 



The subclavius muscle exists under the form of a stemo- 

 scapular band, arising fleshy from the first rib, and passing 

 beneath the clavicle to be inserted into its outer sixth, into 

 the upper border of the acromion process, and into the entire 

 length of the upper margin of the scapular spine. This 

 muscle did not resemble the arrangement described by Prof. 

 Rolleston (Trans. Linn. Soc. vol. xxvi. p. 626). In the 

 Wombat examined by him the muscle arose thick and fleshy 

 from the first rib, and was inserted into the outer end of the 

 clavicle and, by means of the fascia covering the supra- 

 spinatus muscle, into the whole length of the spine of the 

 scapula ; before its insertion it Avas joined by a fine tendon 

 from a delicate muscular belly arising from the sixth costal 

 cartilage, and homologous with the muscular fasciculus in the 

 crocodile which rvms from the second stemo-costal cartilage to 

 the sternum, in series with the external oblique and outer 

 intercostals. As I was acquainted with Prof. Rolleston's de- 

 scription, when dissecting the animal I looked most carefully 

 for this curious arrangement, but was disappointed ; for I saw 

 no sign of any prolongation from below attacjied to the sub- 

 clavius. The insertion of the rectus abdominis was clear and 

 tendinous into the first rib ; and the only other muscle whose 

 fibres could have ruii into it from below was the rectus tho- 

 racis {vide infra) ; but there was no sign of any fusion in our 

 specimen. Professor Rolleston's specimen seems to have been 



