1901.] XlLii xUUSCLiES OF THE L'NGLfJjATA. 70i 



Tragulidte (20, 21, 23), Cervida? (25, 26, 27, 2S), aud Bovida) (32, 

 33, 34, 35, 36, 3S, 39, 40, 41, 43, 48, 49) it is very well marked 

 and forms the chief flexor of the carpus. In the Tapir (54) it is 

 chiefly inserted into the metacarpal bone oE the minimns. In the 

 Equida? (56, 58, 59, 61 ) one part goes as usnal to the i)isiform 

 with the flexor carpi ulnaris, the other is inserted into the rudi- 

 mentary fourth metacarpal. In the Ehinoceros (63) it is ligured 

 but not described, it seems to be largely inserted into the meta- 

 carpal bone of the annularis. In the Hyrax (67) and Elephant 

 (74,77,78,79) the mnscle, though still an important flexor, is 

 chiefly inserted into the metacarpal of the minimus. The con- 

 version of this muscle from an extensor to a flexor is correlated 

 with two compensatory changes : firstly, the extensor carpi radialis 

 is much enlarged and does all the extension of the carpus; secondly, 

 the flexor carpi ulnaris is reduced in importance and its oleeranal 

 head is often absent. 



The ner^•e-supply is the posterior interosseous in the Pig, Duiker- 

 bok, Sheep, Hyrax, and Elephant. 



Supinator brevis. — This muscle is described by Broun as 

 entirely absent in the Ungulata, and A^■itll two exceptions we can 

 confirm his statement. In the Pig (Y.) Lesbres found it once, 

 and Chauveau (II.) says that in this animal it is extremely thin. 

 In our specimens of Suidfe (11, 14) no trace of it could be found. 

 In the Hyrax (68) we found it as a mere tendon, which is con- 

 tinued into the superficial plane of the extensor ossis metacarpi 

 pollicis ; but in Mivart and Murie's animal (67) there is no meu- 

 tion of it, though possibly the muscle which these authors describe 

 as supinator longus may, in reality, be supinator brevis. The 

 muscle was so aborted that we coulcl trace no nerve to it. 



Extensor ossis metacarpi pollicis. — In the Hippopotamus (3) 

 this rises from the shaft of the ulna, and is inserted (1) into the 

 radial side of the carpus. 



In the Suidae (4, 5, 7, 9, 11, 13, 14) it is small, and rises from 

 below the middle of both forearm bones to be inserted into the 

 proximal end of the metacarpal bone of the index. 



In the Tragulidas (20, 21, 22, 23) it rises from the ulna, and 

 has the same insertion as in the Suidae ; in our specimen (21) it 

 was almost entirely tendinous, but in Kinberg's (20) seems to be 

 well developed, since it rises from the lower half of the ulna. In 

 the Camelidte (15, 16), Cervida^ (26, 27, 28), Giraffidfe (29), and 

 Bovida) (32, 33,36, 38, 39, 43, 48, 49) it is inserted into the 

 canon-bone (3rd and 4th fused metacarpals), but sometimes (26^ 

 27, 28, 49) a sesamoid bone is found in its tendon which, from 

 careful examination of the Duiker-bok (49), we believe is the 

 vestige of the index metacarpal. In the Tapir (54, 55) it is 

 weW developed, rises from almost the whole length of the radius 

 and ulna, and is inserted into the index metacarpal. In the 

 Horse, Bronn (VI.) says it is absent, but Chauveau (II.) and 

 Lesbres (V.) agree that it is present, though feeble, and inserted 

 into the rudimentary index metacarpal. In the Ehinoceros (63, 



Proc. Zool. Soc— 1901, Vol. II. No. XLVI. 46 



