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PROFESSOR A. MACALISTER ON THE 
nearly parallel to the posterior border of the acromial deltoid, showing its deltoid nature 
In Noctulina altivolans none of its fibres are meso-scapular ; they all arise from the 
posterior margin. In Vampyrops its origin is also posterior. The insertion in all is 
into the external side of the humerus, below the external tuberosity and under cover 
of the acromial portion ; the insertion is single in Pteropus and its allies, except Pt. edulis, 
double in Vampyrops and Artibeus and Pt. edulis ; in the two former the two slips of 
insertion are a considerable distance apart. In Plecotus , Vespertilio , Vesperuyo , and 
Scotophilus the insertion is single also. In Megaderma a few fibres of the trapezius are 
continued into its upper border. 
In Megaderma this muscle is very deltoidean in appearance in the direction of its fibres ; 
it is least so in Cephalotes , in which, as in Noctulina , no fibres arise from the spine of the 
scapula. 
Professor Humphry considers this muscle as teres minor, Cuvier more properly recog- 
nized its deltoidean nature, Meckel confounded it with the infraspinatus, which he 
describes as very thick. That it is the scapular deltoid is plain from its position over- 
lying the infraspinatus and its fascial relation, lying between two laminae of the infra- 
spinous fascia, and from its coexistence with a beautiful little teres minor ; indeed the 
only feature not deltoidean about it is its transverse direction, a condition which gives it 
great power in rotating and retracting the humerus. 
Supraspinatus (Plate XIII. fig. 11, c ) is a moderately strong muscle, penniform in struc- 
ture, and placed under a strong fascia, whose upper border is thickened into a very strong 
suprascapular ligament ; it is larger than the infraspinatus in Pteropus, smaller in Ceplia - 
lotes and Megaderma ; the difference between the two, however, is very slight. Meckel 
says the infraspinatus is much the larger, because he included the last muscle together 
with the infraspinatus proper under this head ; its tendon crosses the upper part of the 
joint, and is in contact with the synovial membrane in Macroglossus, the capsule being 
deficient under it. 
Infraspinatus (Plate XIII. fig. 12, h) is proportionally largest in Phinolophus diadema 
and speoris , being more than twice as large as the supraspinatus. In no species did I find 
any difficulty in separating it from the supraspinatus, although Meckel says they are 
scarcely separable ; it is separated from the deltoid by a deep layer of fascia, and a 
strong spino-glenoid ligament lies between it and the supraspinatus ; its tendon is closely 
applied to the capsule of the shoulder, and is inserted into the greater tuberosity below 
the last. In Megaderma this muscle is elongated and penniform, and overlapped by the 
teres major. 
Teres minor is a beautiful little muscle, whose existence has not been noticed by any 
anatomist ; it lies under cover of the infraspinatus ; in Pteropus edulis it was half an inch 
long, and its insertion was a quarter of an inch broad (Plate XIII. fig. 12, i) ; it arises 
from the axillary costa, as usual, for about a line or a line and a half; its tendon of origin 
crosses over the triceps longus, becomes fleshy, and is inserted below the infraspinatus 
into the greater tuberosity ; and its insertion is easily distinguished from that of the last 
