46 PROCEEDINGS OP THE ACADEMY OF [1897. 



The Extensor pollicis longus of Burmeister is not present in T. 

 fuscus. It may be found in the pollical slip of the deep extensor as 

 named in the foregoing paragraph. 



The Flexor pollicis brevis and the Abductor pollicis brevis form 

 one muscle. Burmeister separates them. 



The Abductor pollicis arises from the fibrous tissue deep in the 

 palm over the Palmar interossei. It has no bony origin whatever. 

 Burmeister assigns an origin from the third metacarpal bone. His 

 figure gives the impression of an origin from the fourth metacarpal. 



The Opponens pollicis is absent. Burmeister describes and fig- 

 ures this muscle. The Abductor indicis is a small muscle ; it is de- 

 scribed by Burmeister. 



The Abductor minimi digiti embracing the Flexor brevis minimi 

 digiti are as in Burmeister's description. The muscles are imperfectly 

 differentiated. 



The Palmar interossei. — The muscles occupy the opposed sides of 

 the second and third digits, and of the third and fourth digits as 

 given by Burmeister. The pair of muscles for the third and fourth 

 fingers form a fleshy union at the distal end of the first phalanx and 

 the proximal end of the second. Traction flexes the finger power- 

 fully. The muscle to the fifth finger does not flex the finger but 

 extends and abducts it. For the fourth and fifth fingers the arrange- 

 ment is as follows : A muscle arises from unciform bone and lies on 

 the radial side of the distal end of the fifth metacarpal bone. (1). 

 A fleshy muscle extended forward to the distal end of the first pha- 

 lanx of the fifth finger. (2). From the samehypothenar mass with 

 the foregoing muscles is of a spindle shape, which lies at the ulnar 

 side of the fourth finger ; it becomes a fine thread at the second pha- 

 lanx into which it is inserted. Of this group Burmeister briefly 

 says, "the third pair is inserted on the opposed sides of the fourth 

 and fifth fingers." 



The Dorsal interossei are four in number and arranged as follows : 

 Second and third fingers one to each side of the first and second 

 phalanges ; one to the radial side of the fourth digit. All the fore- 

 going have spindle-shaped bellies, which arise from the proximal ends 

 of the respective metacarpal bones. A somewhat distinct muscle is 

 pyramidal and arises from nearly the entire length of the fifth met- 

 acarpal bone as well as the palmar aspect of the fourth and fifth 

 metacarpal bones. The palmar association of the dorsal muscle is 

 marked and confirms Ruge's thesis that these muscles are derivative 



