1898-99. ] THE ANATOMY OF THE ORANG OUTANG, 593 
EXPLANATION OF PLATES. 
The following plates are drawings from dissections made by the author :— 
PLATE III. 
Fic. 1.—Dissection of the posterior aspect of the neck and shoulder of the Orang 
Outang. 
acrom,, acromion process ; c/av., clavicle ; ¢.a.m., external auditory meatus ; 
z.spin., infra spinatus ; /.a.s., levator anguli scapulae ; 7,0., omo cervicalis ; 
rhom., rhomboid; s. spzz., supra spinatus; 5s. mag., serratus magnus ; 
trap., trapezius ; ¢, mzn., teres minor. 
PLATE IV. 
Fic. 2.—Dissection of the anterior aspect of the chest wall and shoulder of the Orang 
Outang. 
acrom., acromion process; clav., clavicle; cor., coracoid process; Delt., 
deltoid ; H., humerus ; Z. mzz., pectoralis minor ; f. m. 1, the pars costo- 
abdominalis of the pectoralis major ; 4.7. 2, the pars sterno-costalis of the 
pectoralis major ; £.7. 3, the pars sternalis of the pectoralis major. S. 7., 
sterno mastoid. 
Fic. 3.—Representation of the mode of insertion of the pectoralis minor muscle. 
acrom., acromion process; clav., clavicle ; cor., coracoid process ; zg. 1 and 
lig. 2, continuation of the fibres of insertion of the pectoralis minor muscle 
into the clavicle and the acromion process ; #. #zz., the tendon of insertion 
of the pectoralis minor muscle passing to the coracoid process. 
Fic. 4.—The arrangement of the interossei muscles in the Orang Outang, as they 
appear in their relation to the metacarpal bones, on transverse section 
through the metacarpus. 
d.7., dorsal interossei ; v. z., palmar interossei. 
PLATE V. 
Fic. 5.—Dissection of the short muscles of the thumb and the little finger in the Orang 
Outang. 
ab.m.d., abductor minimi digiti; "a4.P., abductor pollicis ; ad.o.f., adductor 
obliquus pollicis ; a.¢.4., adductor transversus pollicis ; /., palmar fascia ; 
f.6.p. 1, f.6.p. 2, outer and inner heads of the flexor brevis pollicis ;_77.4.7.d., 
flexor brevis minimi digiti ; 0f.7.d., opponens minimi digiti; 0.4., opponens 
pollicis. 
Fic. 6.—Dissection of the interossei muscles of the hand in the Orang Outang, viewed 
from the palmar aspect. 
Y.2. 1, U.t. 2, Vet» 3, palmar interossei, d.7.1, dz. 2, d.2.3, @.2.4, dorsal interossei. 
