162 PROCEEDINGS OF THE ACADEMY OF [1880. 



portion of fourth, fifth, sixth and seventh ribs. This distinction in 

 origin is partly visible even in man. There was nothing notice- 

 able about the pectoralis minor or subclavius, supraspinati or 

 teres. The latissimus dorsi, as in all monkeys, gave off the slip 

 the latissimo condyloides, which, however, in the Orang scarcely 

 reached the condyle, and was pierced hy the ulnar nerve. The 

 biceps, triceps, and brachialis anticus were well developed, and 

 the external cutaneous nerve passed through the coraco-bracllialis 

 as in man. The anterior aspect of the forearm was quite human. 

 The pronator radii teres arose b}^ two heads, between which passed 

 the median nerve. The flexor carpi radialis and ulnaris and the 

 palmaris longus were well developed. The flexor sublimis did not 

 differ from that of man. The flexor profundus was rather sepa- 

 rated into two portions, one for the under and the other for the 

 remaining fingers. There was no trace of a flexor longus pol- 

 licis either as a distinct muscle or as a slip from the flexor pro- 

 fundus. The abductor, flexor brevis, adductor and opponens 

 pollicis, abductor flexor brevis, and opponens minimi digiti, and 

 the lumbricales were all present. As regards the back of the fore- 

 arm, the supinator longus arose higher than in man. The supi- 

 nator brevis, and extensor radialis longior and brevior, extensor 

 ossi metacarpi pollicis and exterior secundi internodii pollicis did 

 not differ from those in man. The absence of an extensor primi inter- 

 nodii pollicis was noticeable, as was also the fact of the extensor 

 indicis giving a slip to the middle finger and the extensor minimi 

 digiti one to the ring finger, making eight tendons supplying the 

 back of the fingers with the four from the extensor communis 

 digitorum. The interossei were the same as in man. Briefly', the 

 upper extremity of the Orang in its muscles differed essentially 

 from that of man in the absence of the flexus longus, and primi 

 internodii pollicis and in the presence of the additional tendons 

 to the ring and middle fingers. The Orang agreed with the 

 Gorilla in not having a flexor longus pollicis, but disagreed with 

 it in having the pronator radii teres arising by two heads, in the 

 presence of a palmaris longus, in the additional tendons for ring 

 and middle fingers, and in not having the extensor primi internodii 

 pollicis. As compared with the Chimpanzee, the Orang agreed 

 in reference to the pronator radii teres and palmaris longus, but in 

 the extensor ossi metacarpi pollicis being single, and in the 

 absence of the flexor longus pollicis as a slip from the pro- 



