702 MESSRS. B. C. A. WINDLB AND P. G. PARSONS ON |'DeC. 17, 



64) it has the same attachments, but in 63 an extra head was 

 found coming from the external condyle ; there is just a possi- 

 bility that this is really supinator brevis. 



In the Hyrax (67, 68, 71) the exteusor pollicis is large and is 

 inserted into the rudimentary metacarpal bone of the pollex ; in 

 our specimen, as we have mentioned before, the supinator brevis 

 is continued into it, and this we think may account for the 

 condylar head in Beddard and Treves's Ehinoceros. In the 

 Elephant (74, 77, 78) the muscle runs from the radius and ulna 

 to the metacarpal bone of the pollex, and in 78 to that of the 

 index also. In Paterson and Dun's Elephant (79) the muscle 

 was inserted into the trapezium and 1st metacarpal. The nei'\"e- 

 supply is the posterior interosseous. 



Extensores 'primi et secundi internodii pollicis. — The only record 

 of these muscles which we have been able to find is in the 

 Elephant (74), where Miall and Greenw^ood found a slip from the 

 extensor profundus digitorum going to the pollex, but this was not 

 seen in 77 or 78. 



Extensor profiindiis digitorum. — This muscle includes the 

 extensor indicis. In the Pig (5, 6) it was found passing from the 

 forearm below the origin of the ext. oss. metacarpi to the index 

 and medius digits, but we did not find it in our Pig (11) or 

 Peccaiy (14), In the Elephant (74, 77, 78) there is one tendon 

 to the index. In no other ungulate was any trace of it found. 



Thenar Muscles. — In only three Ungulates are there any traces 

 of these muscles. In the Pig (7) Cuvier and Laurillard fi.gure an 

 abductor indicis which, from its position, may be an abductor 

 pollicis which has shifted its insertion. In the Hyrax (67 ) 

 Mivart and Murie found two muscles, possibly abductor and flexor 

 brevis ; in our specimen {Q'^) there was onl}"" one rudimentary 

 one, while Meckel (71) did not find any at all. In the Elephant 

 (74) Miall and Greenwood found a muscle running from the os 

 magnum to the sesamoid bone on the pollex, perhaps a flexor 

 brevis pollicis ; while Paterson and Dun (79) found two distinct 

 muscles — an abductor risiug from the trapezium, and a flexor 

 brevis rising by two heads, from the trapezoid and the shaft of 

 the 1st metacarpal respectively, and being inserted into the 

 sesamoid bones at the head of the metacarpal. Both were supplied 

 by the median nei'A''e. These muscles are not recorded in other 

 Elephants, nor are they present in the College of Surgeons 

 specimen (78). 



Hypotlienar Muscles. — An abductor minimi digiti rising from 

 pisiform is present in the following animals :— Hippopotamus (1), 

 Pig (4, 6, 7, 11), Peccary (14), Chevrotain (20), Water-Chevrotain 

 (28) (apparently), Tapir (55), Ehinoceros (63), Hyrax (67, 68), 

 Elephant (74, 77, 78, 79). In the last animal (79) there is also 

 a flexor brevis minimi digiti. 



Oblique Adductor Muscles. — This layer of muscles is found onlj^ 

 in the Pig (4, 6, 11, 14), the Chevrotain (20), and the Elephant 

 (74, 79) ; in most of these there are adductores indicis et minimi, 



