5i8 MR. J. C. GALTON ON DASYPUS SEXCINCTUS. 



fifth digit ; while the other, which is inserted into the radial side of the base of the 

 ungual phalanx, arises from the ligament stretched between the above nodule of the 

 trapezio-trapezoid bone and the middle digit. 



This muscle is described as the internal interosseus of the fifth digit, by Dr. Mac- 

 alister 1 . 



Abductor pollicis. — A short, but well- developed fusiform muscle, which arises from 

 the palmar fascia, close to its insertion at the small sesamoid which lies to the outer side 

 of the scaphoid bone. It is inserted into the proximal phalanx of the pollex, on its 

 external aspect. 



Opponens pollicis.— Also well developed. It is a fusiform slip, which arises just 

 posterior to a rounded projection from the palm, probably belonging to the trapezio- 

 trapezoid bone, and is inserted, below the preceding muscle, into the radial side of the 

 base of the proximal phalanx of the pollex. 



Flexor brevis (or Abductor) pollicis.— A muscle similar, in size and shape, to the pre- 

 ceding; arises just anterior to the above-described process of the trapezio-trapezoid bone, 

 also from a strong ligamentous raphe, which passes from the above nodular projection to' 

 the base of the proximal phalanges of the index and middle digits, and from which most 

 of the other palmar interossei arise. It is inserted into the base of the proximal phalanx 

 of the pollex, on its ulnar side. 



Literossei.-A. muscle, broad and fleshy, arises beneath the origin of the preceding 

 muscle and beneath the strong ligament which stretches from the proximal phalanges of 

 the index and middle digits to the palmar nodule of the trapezio-trapezoid bone. It is 

 inserted, by a round strong tendon, into the base of the proximal phalanx of the index, 

 on its palmar aspect, and is also prolonged over the radial side of the root of this digit 

 to join the extensor tendon, or its sheath, by a broad tendinous expansion over the 

 dorsum of the proximal phalanx. 



T , ™ S T? le ; WMch SGemS t0 be f™ cU ™ all y an abductor mdicis, is considered by 

 JSflS T t0 ^ ^ diSplaCGd homolo ^ e of the ^ep head of the flexor brevis 



britl^T' 7 US v° rm ^^ ariSGS Ween the °^ inS 0f the P reced -S and the flexor 



uLTT ^ C T S ° bliqUely ^ ^"^ ° f the middle ^ and, becoming 



tetS nhl " ," radkl SMe ° f ^ f0Urth ^ t0 be ^ into the base of 



its ungual phalanx, on the same side. As it croiw* tho m ,vi,n„ u •. m • j • j. 



ny a muscle next to be described. *** * * CTOSSed l ° tUm 



metaZaI e oft! a1 ' SJ^-T^ ^ ^ * " «#* ™^ as »* "« «« the 



mt£ Isoe* ^ f ' r d T 1S iUSert6d ^ the P r ™> P^-* ^ t"e index, 



nJ^;zti:^% appears to take orisin from the pai - surface ° f 



- -1 sides of the index and f^t^^^ S^K 



1 Annak and Ma S- of Nat. Hist., I c. p. 318. 



which appears to be 



Loc. cit. p. 319. 



