MYOLOGY OF THE CHEIROPTERA. 
131 
1. Retrahens aurem (Plate XIII. fig. 7, b) in Plecotus is strong and prominent, arising 
from the occipital line, passes outwards to be inserted into the back of the concha ; a 
few fibres join the muscle of one side to its fellow of the opposite across the mesial line. 
In Synotus its arrangement is similar ; in Vespertilio, Vesperugo, and Noctulina it is thinner 
and wider, and is attached to the outer part of the occipital bone. In Pteropus and 
Macroglossus it is also thin, wide, and triangular. In Vampyrops it is double (Plate XIII . 
fig. 6, a , b), the lower muscle starting from the occipital protuberance, the upper from 
the curved ridge external to the occipito-pollicalis. In Cejplialotes it is small and thick ; 
on the left side in my specimen a band came from the occipito-pollicalis to join this 
muscle, lying superficial to the sterno-cleido-mastoid. In Megaderma the retrahens con- 
sists of three slips (Plate XIII. fig. 2, b, c), arising in common with the occipito-frontalis, 
of which the middle is the longest and the inferior the shortest. In Myotus it is still 
further fasciculated ; Kolenati found it in five bundles. 
2. Attollens aurem (Plate XIII. fig. 6, c) in Vampyrops and Artibeus is wide and thin ; 
most of its fibres run downwards and forwards ; it arises from the epicranial aponeurosis. 
In Megaderma it is wider and thicker, very large in Plecotus , and attached from the 
occipital curved line to the anterior margin of the epicranial aponeurosis ; not quite so 
extensive in the other Vespertilionine Bats. In Cephalotes it arises from the mesial line 
of the scalp, overlying the epicranial aponeurosis (Plate XV. fig. 1, k). 
3. Attrahens aurem (Plate XIII. fig. 5, f) is very large in Megaderma, and arises 
from the supraorbital ridge as well as from the zygomatic arch ; it is inserted into the 
anterior surface of the concha and tragus; in Plecotus and Synotus it is small and thick. 
In Noctulina altivolans it consists of two parts, one normal from the zygomatic arch, the 
other a transverse band on the forehead passing from the one ear to the other above 
the supraorbital ridges, and over the anterior bellies of the occipito-frontales. In 
Vampyrops the muscle is strong and its lower border rounded. In Cynonycteris it is 
single and much weaker, and it is moderate in development. In Artibeus jamaicensis, 
in Pteropus, and the Kiodote ( Macroglossus minimus) it consists of a thin sheet of 
muscle overlying and attached to the temporal aponeurosis (Plate XIII. fig. 3, e). In 
Cephalotes its origin is from the zygomatic process of the temporal bone under the 
zygomatic muscle ; it passes upwards and backwards to the ear, forming a strong band 
of fibres. 
In Plecotus Kolenati has found a special depressor tragi passing from the concha to 
the tragus, which it depresses ; this corresponds to the tragicus of the human ear ; this 
exists in the Horseshoe Bats and in Megaderma lyra, but I found it in no others. 
The nose has one large pair of muscles in every species, the procerus nasi (Plate XIII. 
fig. 6, e) (pyramidalis would be a misnomer in every case) ; this varies in size, being small 
and indistinctly joined to the frontalis in Plecotus, larger in the Barbastelle (Synotus), 
inseparable from the frontalis and small in Megaderma, enormously large and thick 
and with a special frontal origin in Bhinolophus diadema, speoris, ferrum-eguinum, and 
hipposideros, also large, but with no separate origin, in Cephalotes. In Vampyrops 
vittatus it is likewise large, and has a special bony attachment. In Artibeus it is 
