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PROFESSOR A. MACALISTER ON THE 
phalanges of each. In Macroglossus minimus it is inserted into the pollex and index, and 
by a fine thread forming the origin of the polliceal interosseous of the middle finger. In 
Plecotus it is also inserted into the pollex and index. In Vesperugo and Vespertilio it is 
similar. In Cephalotes its origin is as in Vampyrops , and its insertion as in Macroglossus. 
In Megaderma its origin is merely condylo-radial, and the insertion by three tendons 
into pollex, medius, and ring, the last tendon being very feeble ; it is the same in Bh. 
speoris and diadema , only the ring tendon goes to the radial interosseous of that digit. 
Cuvier says this muscle has five slips to the five fingers, Meckel says four ; both of 
which statements are incorrect, as will be seen. In Artibeus jamaicensis its origin is 
from the humerus, radius, and ulna, and its insertion into the pollex and medius. In 
Cynonycteris amplexicaudatus it is very similar to the arrangement in Cephalotes. 
In the left forearm of my specimen of Vampyrops vittaius I found a special flexor 
annularis, as a small thread of muscle ending in a slender tendon which passed to the 
last phalanx of the ring-finger ; it was only found in this specimen and in the Cephalotes , 
and seemed like a detached slip of the flexor profundus digitorum. 
Extensor carpi radialis longior (Plate XIV. fig. 4, j) is separate in all except Plecotus, 
Scotophilus, and the Pipistrelle ; in the others it had a perfectly simple and normal course, 
and was inserted into the base of the second metacarpal bone ; it is the smaller of the 
two, and of course the more superficial ; the radial nerve lies in front of it. 
Extensor carpi radialis brevior (Plate XIV. fig. 4, k) is equally constant and has its normal 
insertion. I found no sign in any species of the extension of accessory slips from this 
tendon to the fourth and fifth metacarpal bones, like those described by Professor PIum- 
phry ; so I suppose that they also should be considered as muscular anomalies, especially 
as it was only in one of his specimens (male) that he found them. Meckel describes 
this muscle as inserted into the three outermost metacarpal bones, but I found no fibres 
in any species extending to the polliceal metacarpal. 
Extensor carpi ulnaris (Plate XIV. fig. 4, a) is a very small muscle when present, and 
I missed it in the smaller Vespertilionine specimens. In Megaderma and Bhinolophus it 
is extremely small ; it is in all principally ulnar in its origin, entirely so in Noctulina, 
condylo-ulnar in the others ; it is inserted into the fifth metacarpal in most, into the fourth 
and fifth in Noctidina, into the same bones in Artibeus and in Cynonycteris , extending 
to the first phalanx in Cephalotes ; it is purely metacarpal in insertion in Macroglossus. 
Extensor ossis metacarpi pollicis (Plate XIV. fig. 4 ,f) is constant in all the Cheiroptera, 
and displays no remarkable feature, arising high upon the back of the forearm from 
the ulna and radius ; its tendon passes, as usual, over the radial extensors of the carpus, 
and in most of the species is inserted into the base of the metacarpal bone of the pollex 
simply. A sesamoid bone exists in almost every species at the lower end of the tendon 
where it lies on the wrist-joint. In Cephalotes it rises as high as the elbow-joint, to the 
external ligament of which some of its fibres are attached. In Megaderma it has a 
large radial attachment. I found no special insertion into the radial extremity of the 
transverse process of the os magnum in any species ; but in some of the large ones, as 
