2-16 MR. G. E. DOBSON ON CAPROMYS MELANURUS. [Apr. 1, 



plantar fascia, from the os calcis, and from a flat sesamoid bone con- 

 nected by ligament with the scaphoid and lying on the scapho-cunei- 

 foim articulation, and forms three muscular masses ending in three 

 tendons, which, joined by muscular fibres from the deep part (which 

 arises from the superficial surface of the united tendons of the flexor 

 digitorum jibularis and flexor digitorum tibialis), form the perforated 

 tendons for the three middle toes, the perforated tendon for the fifth 

 toe being derived altogether from the muscular fibres arising from 

 the long flexor tendons. 



Flexor accessorius pedis is well developed, arising from the os calcis ; 

 forms a broad flat muscle, which is inserted into the tibial margin of 

 the tendon of the flexor tibialis from a point above its union with the 

 tendon of the flexor digitorum Jibularis to where the tendon for the 

 hallux is given off. 



Lumbricales. — There are four well-developed lumbricales : the first 

 arises from the fibular side of the halluceal tendon and is inserted 

 into the tibial side of the first phalanx of the second toe near its 

 base ; the second arises from the tibial side of the tendon for the 

 third digit, and is inserted similarly into the same digit ; the third, 

 from both the third and fourth tendons, is inserted similarly into the 

 fourth toe ; and the fourth, from the fibular side of the fourth tendon, 

 is inserted into the fifth toe. 



Abductor ossis metatarsi hallucis. — This is a short muscle extend- 

 ing from the scaphoid bone and the flat sesamoid bone covering the 

 scapho-cuneiform articulation to the tibial side of the base of the 

 first metatarsal. 



Adductor hallucis, indicis, minimi digiti. — Of these muscles the 

 first-named arises from the deep plantar fascia and ligamentous 

 structures at the base of the second metatarsal, and, passing forwards 

 and inwards, is inserted into the fibular side of the sesamoid bone 

 covering the metatarso-phalangeal joint of the hallux. The adductor 

 indicis and add. minimi digiti arise together from the ligamentous 

 structures at the bases of the third and fourth metatarsal bones, 

 and, continuing united as far as the middle of the third metatarsal, 

 diverge to their insertions into the fibular side of the sesamoid bone 

 at the base of the second toe, and into the tibial side of that at 

 the base of the fifth toe respectively. 



Flexores digitorum breves vel interossei. — There are, as usual, a 

 pair of very distinct flexores breves for each toe, arising from the 

 sides and bases of the metatarsal bones ; of those for the hallux that 

 on the tibial side is much larger and longer, arising as far back as 

 the sesamoid bone and ligamentous structures covering the scapho- 

 cuneiform articulation. 



Interossei dorsales. — There are two representatives of these muscles, 

 namely for the third and fourth toes ; each is fused throughout its 

 muscular part with the plantar interosseous muscle on the tibial side 

 of its metatarsal bone, but forms a distinct tendon which passes 

 forwards between the toes, and, turning upwards, unites over the 

 second phalanx with the conjoined tendon of the extensor communis 

 and extensor brevis digitorum muscles. 



