36 NATURAL HISTORY SOCIETY OF DUBLIN. 



torum was brought into view, arising from the cartilages of the eighth, 

 ninth, and tenth ribs, and inserted by a flat tendon into the cartilage of 

 the first and second ribs. That this supra-costal muscle is but a tho- 

 racic rectus is evident, as in this animal, as well as in Macacus Sinicus, 

 and others, the abdominal rectus was continued into its outer border. 



Another peculiarity in this species of Cebus was the existence of a 

 small muscular slip beneath the coraco-brachialis, which ran from the 

 inferior aspect of the tip of the coracoid process to the anterior part of 

 the neck of the humerus, crossing over the capsular ligament of the 

 shoulder and the tendon of the subscapularis. That this was quite se- 

 parate from the coraco-brachialis seemed unquestionable, as the lower 

 border of its insertion corresponded with the upper edges of the latissi- 

 mus dorsi tendon, which thus separated it from the rest of the coraco- 

 brachialis. 



As this accessory slip, although extending to the humerus, is closely 

 related to the capsule, it may be the representative of the coraco- capsu- 

 lar described by Mr. "Wood as a chance variety in man. This muscle 

 I have found to be very constant in Qnadrumana. I have found it in 

 Macacus, Cercopithecus, Rhesus, and many other genera, as well as in 

 Cebus ; and Mivart mentions its presence in Cercopithecus sabceus, and 

 in Nycticebus tardigradus* 



A scalenus accessorius was likewise present in this animal, separate 

 from the three normal muscles of this name. It was connected with the 

 posterior tubercles of the transverse processes of the fifth and sixth cer- 

 vical vertebrae, and was inserted into the first rib, behind the scalenus 

 medius. This muscle corresponds to the accessory scalenus, which I 

 have on several occasions found in man, and seems quite distinct from 

 the scalenus minimus of Albinus, with which in man I have seen the 

 accessory muscle to coexist. 



The serrati postici made nearly a continuous muscular sheet along 

 the dorsal region, as the superior was inserted into the upper six ribs, 

 while the inferior was attached to the lower six ; and thus the two in- 

 termediate bones were the only ones to which no muscular fibres were 

 attached, and even here a strong connecting aponeurosis took the place 

 of the muscles. 



Mr. "Wood, in his paper on "Anomalies in Human Myology,"! speaks 

 of an interesting specimen in which the palmaris longus was bicipital, and 

 had an inverted belly, and mentions that it "is similar to the arrange- 

 ment in Cebus." My specimens, however, differed from this description, 

 as in these individuals the palmaris longus was represented by a small 

 tendon which sprang from the belly of the flexor sublimis digitorum, and 

 was quite inseparable from that muscle. This I have likewise seen as a 

 human anomaly. A small infraspinatus secundus was present, passing as 

 usual from the axillary border of the scapula to the inferior part of the 

 capsular ligament of the shoulder joint. In one individual this muscle 



* Op. cit., p, 244. 



t " Proceedings of the Royal Society," 1864. 



