330 MESSES. B. C. A. WINDLE AND F. G. PARSOJIS ON [Mar. 7, 



the outer side of that bone is not present. In Myrmecophaga the 

 humeral head of the biceps, already described, may with considerable 

 probability be looked upon as a suppressed and modified brachialis 

 anticus (11, 12, 13). In Tamandua (14, 15) the condition is 

 practically the same. In Cyclotlmrus (17, 18, 19, 20) the muscle 

 rises below the deltoid ridge. In the Dasypodiche the external 

 part of the muscle is present and rises from the neck of the 

 humerus in the usual mammalian manner. This applies to 

 Dasypus (22, 23), Tatusia (25), and Chlamydopliorus (27). In the 

 Maaidce the outer or longhead was found, as in the last-mentioned 

 family, in every case (29, 30, 31, 32, 33, 34). In only one case 

 was the internal head found (29), and in tliat it rose from the 

 front of the humerus below the deltoid ridge. In two cases (30, 

 31) this head was carefully looked for, but without success ; it is, 

 however, frequently so closely fused with the external head that, 

 unless specially sought for, it is ver}^ easily overlooked. In 

 Orycteropiis (35, 36) the external head was present as usual, but 

 the internal head was present, as a few fibres rising from below 

 the deltoid ridge, in one specimen only (35). 



Triceps and Anconeus. — In the Bradypodidiv, Bradyp)us (1, 2, 3, 

 4, 5) and Choloepus (8, 10) have the usual three heads, and the 

 inner of these tends to fuse with the anconeus. In the Myrmeco- 

 pJuu/idce the muscle is often very specialized. Pouchet (II.) 

 describes six heads, three superficial and three deep. The three 

 superficial he calls : (a) " La longue," which is equivalent to our 

 longus, though a few of its fibres rise from the dorsum scapulae 

 and remind us of the arrangement found in some of the 

 Mustelidse amongst the Cai-nivora (Proc. Zool. iSoc. 18D7, p. 394), 

 This arrangement was also found in the E.C.S. specimen (11). 

 (5) " L'accessoire interne," which we have ah-eady alluded 

 to as a displaced latissimo-olecranalis. (c) " L'accessoire ex- 

 terne," which rises by tendon between the two parts of the 

 deltoid and becomes fleshy as it descends. It was not present in 

 the specimen which we examined from the E.C.S. The three 

 deep heads of Pouchet are : (d) " Le vaste interne," (e) " Le 

 vaste externe," and (/) " L'accessoire median." The two former 

 are simply the usual external and internal heads of the 

 muscle, while the third consists of some fibres from the short 

 head of the biceps to the triceps, which we did not find in the 

 E.C.S. specimen. Macalister (13) points out that the internal 

 head becomes tendinous and passes through a groove behind the 

 internal condyle, through which it plays as through a pulley, 

 its tendon then becoming continuous with one of the heads of 

 the flexor of the digits. This remarkable arrangement, also met 

 with in Orycteropus, must, as Macalister remarks, give great 

 additional power to the latter muscle and is a further example of 

 the unusual confluence of usually separate muscles in this Order. 

 In Tamandua (14, 15) the long head is very large, rising from all 

 that part of the dorsum scapulae below the inferior sjjine which is 

 not occupied by the teres major. In one case (15) an additional 



