MYOLOGY OF THE CHEIEOPTEEA. 
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coexists * with the lesser pectoral as an anomaly ; and in one of its conditions it is known 
as the chondro-epitrochlearis. That it is not pectoralis minor is shown by this fact, and 
also by the fact that it is supplied by the anterior thoracic nerve from the outer cord of 
the brachial plexus, not by the middle, which should supply it if it were lesser pectoral. 
Cuvier and Meckel describe a muscle passing in the Bat from the three upper ribs 
to the coracoid process with a broad tendon of insertion ; this they call the pectoralis 
minor. I have not seen the least trace of a muscle like this in the whole course of my 
dissections, nor has Humphry met with it in his Pteropus. 
A strong costo-coracoid membrane underlies the pars clavicularis of the great pectoral 
and covers the subclavius ; this is weakest in Rhinolophus diademct and Cephalotes , 
strongest in Macroglossus. The subclavius (Plate XIII. tig. 13, a) beneath it in all 
passes from the first rib to the clavicle, and has no connexion with any other bones ; its 
origin is tendinous in Megaderma and Plecotus. This tendon is long in the Pipistrelle ; 
its costal attachment is fleshy and tendinous in Pteropus , and is fleshy and from a large 
extent of the first rib in Pteropus, Cephalotes, and Macroglossus. Its insertion is into 
the outer half of the under surface of the clavicle, or the outer seven eighths as in 
Megaderma , or two thirds as in Artibeus. The muscle is proportionally smallest in 
Noctulina. Its non-extension is interesting, as this is the homologue of the levator 
humeri of the bird, whose extension to the humerus is of such importance in avian flight, 
thus indicating the difference between the mechanism of flight in the two series. 
Serratus magnus is a double muscle in all the Bats, and consists of an inferior and a 
superior part ; the former arises from a varying number of ribs below the first, eight in 
Plecotus , Synotus , Vespertilio , and Noctulina , with two slips from the second rib in 
Vespertilio murinus , Vesperugo pipistrellus, and Noctulina, with a single wide slip in 
Plecotus and Synotus. In Macroglossus it is attached to nine ribs, with only one slip 
from the second ; in Artibeus and Vampyrops it is attached also to nine ; in Pteropus 
medius and Pdwardsii to eight, or ten, as in P. edulis ; in Megadermct to nine. Meckel 
describes it as arising from the ribs, except the two last ; it is inserted into the inferior 
and external border of the scapula between the teres major and the subscapularis, some- 
times rising nearly halfway along the axillary margin of the scapula, as in Megaderma. 
In Vampyrops it has an attachment higher up to the posterior border, and a tendinous 
sling stretches from this to the main insertion at the lower angle. 
Serratus magnus superior arises from the first rib in the Bliinolophidee, Phyllostomidge, 
as well as in Vesperugo and Scotophilus. In Noctulina it arises from the upper three ribs 
behind the upper border of the serratus inferior ; in Pteropus it has a second tooth from 
the second rib ; its origin is under the scaleni, and is inserted into the vertebral edge of 
the scapula at its upper angle under cover of the insertion of the levator anguli scapulae, 
from which it is perfectly separate in all the Cheiroptera, even in Megaderma, in which 
the serratus magnus superior arises from the first rib, and from the transverse process 
of the last cervical vertebrae. 
* I figured and described this muscle in Cehvs cwpucinus, Proc. Nat. Hist. Soc. Dubl. 1866, pi. 1. 
