MYOLOGY OE THE CHEIROPTERA. 
149 
fourth to that of the middle finger ; none of these extend beyond the bases of the meta- 
carpals : the muscle as well as the tendon is superficial. In Macroglossus minimus its 
principal origin is radial, and its insertion is by two tendons, one into the base of the 
pollex metacarpal, and one which stretches to the base of the first phalanx of the index. 
Professor Humphry found in Ft er opus Edwardsii that one tendon of this muscle was 
inserted into the sesamoid bone on the ulnar side of the metacarpo-phalangeal joint of 
the pollex. and the other had a slight attachment to the metacarpal bone of the index, 
and was continued on to the base of the second phalanx of that digit. In Pteropus 
edulis it is also simply metacarpal in its insertion, and sends no distinct slip to any of 
the phalanges. In Plecotus this muscle is of extreme tenuity, and is inserted into the 
metacarpal bones of the pollex and index ; in the Pipistrelle it goes to the first phalanx 
of the middle and fourth fingers. In Cephalotes it springs from the inner condyle, and 
its tendon is flattened over the rest at the wrist to be inserted into the metacarpal bones 
of the pollex and index. In Rliinolophus speoris and diadema its insertion is threefold, 
into the pollex, medius, and index ; the slip to the index is very thin, the origin is super- 
ficial, and the fleshy portion very short. In Megaderma it is slender, and its tendon is 
tightly tied to the next; its muscle is deep, arising from the radius; its insertion is into 
the thumb, index, and middle fingers, at their metacarpo-phalangeal articulations : the 
tendons in all are flat, superficial, and in the last especially they are lost in the fascia 
and are not attached to bone. In Artibeus the arrangement is as in Vampyrops ; in 
Cynonycteris it is attached as in Cephalotes (Plate XIV. figs. 1, /, 2, a, & 3, d). 
Taking together the flatness and fascial connexion, the metacarpal insertions and super- 
ficiality at the wrist, where this tendon runs in a separate sheath under a thin band of 
fibrous tissue, but over the main body of the annular ligament, all these together seem 
to indicate that it is a palmaris, not a flexor sublimis. The existence of a polliceal slip 
is not what we might expect in a flexor sublimis. In Noctidina this muscle is absent 
altogether. 
Flexor digitorum communis (Plate XIV. figs. 1, c7, 2, h, 3 ,g, & 5, e ) (profundus of PIum- 
phry) in Noctidina arises from the inner condyle, from the upper third of the radius, 
and is inserted into the base of the first phalanx of the pollex, into the second phalanx 
of the medius, and the origin of the interosseous muscle for the polliceal side of the ring- 
finger. In Pteropus Edwardsii and medius it arises from the inner condyle, from the 
radius and ulna ; it passes under a strong arch at the wrist to be inserted into the last 
phalanx of the pollex, into the index and middle fingers at their last phalanges ; the 
tendon to the middle finger in the female Pteropus Edwardsii became fleshy for a con- 
siderable part of its extent (Humphry). In Pt. edulis it was as in the other species, 
but no part of the tendon became fleshy. 
This is the only long flexor muscle of the digits present in most of the Yespertilionine 
Bats, as Professor Aeby describes (7. c. p. 66). In Vampyrops it arises from the condyle, 
upper third of the radius and ulna ; its tendon passes under the transverse process of the 
os magnum, and is inserted into the pollex and medius, extending to the terminal 
mdccclxxii. x 
