Prof. A. Macalister on the Anatomy of the Derriah. 63 



The most important points of the muscular anatomy of this 

 animal are as follows : — 



The trapezius was indivisible, and was inserted into the 

 outer half of the clavicle. The sterno- and cleidomastoids 

 were inseparable and large, being nearly an ounce in weight. 

 The omohyoid was a single-bellied muscle, with no tendinous 

 intersection. The trachelo-acromial was large, half the size 

 of the sterno-cleidomastoid. The latissimus dorsi arises from 

 the eleven spines below the fifth dorsal, and from the posterior 

 fifth of the iliac crest, but from no ribs. The rhomboid is 

 indivisible, but consists of the usual occipital and dorsal por- 

 tions. The serratus magnus is in three parts, and extends 

 from the second cervical transverse process to the tenth rib ; 

 the uppermost and lowest of these are strong, the middle 

 weaker. 



Serratus posticus superior is attached to the third, fourth, 

 and fifth ribs, the inferior to tlie ninth, tenth, eleventh, twelfth, 

 and thirteenth ribs. The pectoralis minor arises from the 

 cartilages of the second to the seventh ribs, and from the 

 abdominal aponeurosis. The deltoid is easily divisible into 

 scapular, acromial, and clavicular parts ; of these the acromial 

 is the largest, the clavicular about half its size, and the sca- 

 pular still smaller. The subclavius does not extend beyond 

 the clavicle. The capsular muscles of the shoulder are as 

 usual, and in the following proportions of relative develop- 

 ment :—supraspinatus = 1, infraspinatus = 1*34, subscapu- 

 laris = 1*6, teres major 0"6, teres minor = 0*17. There is a 

 pectoralis quartus from the cartilages of the lowest ribs, in- 

 serted under the pectoralis major and below the pectoralis 

 minor into the shoulder-capsule. -The coraco-brachialis is 

 double — a short muscle (c. brevis of Wood) weighing 0*07 of an 

 ounce, and a longer, going to the lower third of the humerus, 

 weighing 0'14. The two heads of the biceps humeri were 

 inseparably united ; and the entire muscle was nearly 2 ounces 

 in weight : this muscle was 2*3 times as heavy as the bra- 

 chialis anticus ; and the triceps (which is divisible into long, 

 outer, and inner parts) is exactly double the sum of these two 

 flexors. The coracoid head of the biceps was fleshy. The 

 dorsi epitrochlearis was thin, extending halfway down the 

 arm, and half an ounce in weight. 



There are two anconei, an outer and an inner. 



Among the forearm muscles the peculiarities were : — The 

 palmaris longus fleshy for the upper half of the forearm, and 

 half the size of the flexor carpi radialis. The flexor sublimis 

 has no radial origin. The flexor digitorum profundus and 

 pollicis are inseparably connected, and there is a condyloid 

 head separated from the rest by the median nerve. The polli- 



