MYOLOGY OF THE CHEIROPTERA. 
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Pteropus edulis, a fibrous band connected the sesamoid bone to it ; still in these, as in 
the others, the main insertion is into the pollex metacarpal. The sesamoid bone is very 
large in some of the species, and has a distinct articular facet for the scapho-lunar in 
Eleutherura : I did not find it in Scotophilus hesperus ; but the parts are so small that I 
may have easily missed it (Cuvier says of this muscle that it crosses the extensor carpi 
ulnaris at the wrist ; but this is obviously an error). 
Extensor secundi internodii pollicis arises from the back of the radius at its lower 
half ; it crosses the radial extensors at the wrist, and is inserted as usual. In Vampy- 
rops I missed it in the left arm, but found it in the right. In Megaderma it springs 
from the olecranon, but it is very large in Rhinolophus diadema. In all the other 
specimens it is normal and large. 
Extensor indicis is a separate muscle in all but Megaderma and Cephalotes, in which 
it is joined to the extensor digitorum; it arises from the radius and is inserted into the 
last phalanx of the index, but only into the metacarpal bone in Megaderma. The exist- 
ence of this muscle was not recognized by Meckel or Cuvier, and Aeby says that he 
failed to find it in the Bat (loc. tit. p. 60). 
In Macroeglossus minimus I found this muscle replaced by an extensor of the pollex 
and index, similar to the muscle which exists in the Dog, Fox, Panther, and Wolf. 
It arose below the extensor ossis metacarpi pollicis, and was inserted into the first 
phalanges of the pollex and index. In Cynonycteris and Plecotus I found a corresponding 
muscle coexisting with the extensor indicis and the extensor secundi internodii pollicis, 
but I have not found it in any other species. 
Extensor digitorum communis arises from the outer condyle of the humerus as well 
as from the radius ; it passes along the ulnar side of the forearm, and at the wrist projects 
to the ulnar side ; it ends in three tendons, which pass to the three ulnar fingers. In 
Megaderma the tendon for the second finger is very weak ; in Cephalotes the extensor 
indicis is slightly joined to it; the union is more close in Megaderma. Cuvier describes 
this muscle as inserted into the last phalanges of all the fingers, but in none does this 
muscle proper send a tendon to the index. As all the tendons cross on the ulnar side 
of the wrist, that for the middle finger crosses the back of the fifth, fourth, and third 
metacarpals, that for the fourth crosses the fifth and fourth, and so on. 
The muscles of the manus are as follows. For the pollex I have found: — - 
1st. An abductor pollicis (Plate XIV. fig. 5, g), from the scapho-lunar to the base of 
the first phalanx of the pollex ; on its outer side this is present in Macroglossus , Pteropus , 
N octulina, Megaderma , and the other large Bats. 
2nd. Opponens pollicis, arising from the trapezium and scapho-lunar bones, inserted 
into the metacarpal bone of the pollex ; this I have only found in Noctulina and Macro- 
glossus. 
3rd. Flexor pollicis brevis radialis, from the scapho-lunar bone and from the radial 
side of the os magnum to the base of the radial side of the first phalanx of pollex ; it is 
X 2 
