1899.] THE MYOLOGY OF THE EDENTATA. 337 



index as well. In Basypus (22, 23) there are tendons for the 

 index and poUex, but in (24) for the index only. 



In Tatusia there are tendons for the index and medius in (2/)) 

 and for index only in (26). In Chlamydophorus (27) the tendon to 

 the index gives a fascial slip to the pollex. In Manis (29, 32, 33) 

 the extensor indicis alone is present, but in one case (30) there is 

 a polliceal slip as well. Grycteropus has a well-developed extensor 

 profundus, which in two cases (35, 36) went to the index, medius, 

 and annularis, and in another (37) to the index and medius only. 

 It is interesting to notice that whilst in some of these animals 

 the origin is as usual from the dorsal surface of the ulna, in 

 others it seems to have slipped down and the muscle rises from 

 the dorsum of the carpus and closely corresponds to tlie extensor 

 brevis digitorum pedis. This low origin was found in the following 

 animals : Bradypus (1, 4, 5), Choloejius (10), Cyelothurus (17), 

 Manis (30, 33). 



Palmaris brevis. — This muscle was well marked in Bradypus (1), 

 Tamandua (14), and Cyelothurus (18). In Tamandua it was a 

 pecuharly large muscle, filling the great boxing-glove like pad on 

 the ulnar side of the hand. In 3Iyrmecoj)har/a it was very feeble, 

 if, indeed, it was present at all, whilst we failed to find any trace 

 of it in any other Edentate. 



Supinator brevis. — In the Bradypodidce this muscle covers the 

 upper third of the radius. In two specimens of Choloepus (8, 10) 

 it was divided into two layers, between which lay the posterior 

 interosseous nerve, but in another specimen of the same animal (9) 

 this division was not noticed. In the Myrmecophagidce the muscle 

 is insei'ted into the lower part of the radius — Myrmecophacia (11, 

 12), Tamandua (14), and Cyelothurus (17, 18, 19, 20). Among the 

 Dasypodidce the muscle is small in Basypus (22, 23), small or 

 absent in Tatusia (2-5, 2^) and Chlamydopjhorus (27, 28). In the 

 ManidcK, on the other hand, it is inserted into nearly the whole 

 length of the radius (29, 31, 32, 33, 34), and has a sesamoid bone 

 developed in its origin. In Orycteropus (35, 36) the muscle only 

 occupies the upper half of the radius. 



Intrinsie Muscles of the Hand. — We find it extremely difficult, in 

 reading the hterature of the subject, to understand at what depth 

 the various muscles were placed and to which digit precisely they 

 were attached. As it has been always our desire to err less on 

 the side of commission than of omission, we feel bound to omit 

 much which did not appear clear to us, and must therefore confess 

 that our account of these muscles in the Edentata is somewhat of 

 the scantiest. In Bradypus (1) there was an adductor polHcis and 

 also adductors of the index and annularis, which were superficial 

 to the deep branch of the ulnar nerve. An interosseous muscle is 

 present between each of the metacarpal bones. In Cholcepus (8) 

 there is an adductor indicis, belonging to the first layer of deep 

 muscles, which rose from the carpus and was inserted into the 

 ulnar side of the base of the proximal phalanx of the index ; there 

 is also an interosseous muscle on eacli side of the index. In the 



