1905. J AKATOMY OP THE LEATHERY TURTLE. 307 



covers the flexor surface of the wrist and partly from the outer 

 side of metacarpal I. Insertion : upon the penultimate phalanges 

 of digits II., III., IV,, and upon the flexor sin^faceof the pisiform 

 and of metacarpal Y. The parts of the muscle pi-oper to digits 

 II., III., lY. are perforated by the tendons of the deep flexor. 



Ulna-digitil.-Y . (ilexor digitonwip7'ofunch(,s) (text- fig. 64. 67). 

 — Origin : from the whole length of the flexor surface of the ulna 

 and from that of the ulnar half of the carpus exclusive of the 

 pisiform. Insertion ; by four round tendons to the terminal 

 phalanges of digits I.-IY. 



Intrinsic muscles of the hand (text-fig. 64, Y). — These are seven 

 in number. They take origin from the distal parts of the flexor 

 surface of carpus and are inserted upon the metacarpo-phalangeal 

 joints. There are two in connection with the thumb, very much 

 matted together and partly fused with the tendon of the deep 

 flexor ; one to the second digit, having a common origin with the 

 outer one of the two to the thumb ; two to the third digit ; and 

 one each to the outer side of digits lY., Y. 



Ahdomincd Muscles. 



Rectus abdominis (text-figs. 57, 65, 66. 75). — a. Anterior part. 

 Origin : from the plastron about 4 cm. behind the pectoralis by a 

 backwardly concave semilunai' attachment. Insertion : into the 

 anterior margin of the lateral horn of the pubis. The insertion 

 encroaches somewhat upon both dorsal and ventral surfaces of the 

 pubis, 



h. Inner posterior part. Origin : from the hinder edge of the 

 plastron close to the mid-line. Insertion : upon the anterior end 

 of the epipubis. 



c. Outer posterior pai't. Origin : from the hinder edge of the 

 plastron to the outer side of the origin of " 6." Insertion : upon 

 the ventral surface of the latei-al hoi'n of the pubis posterior to 

 the insertion of " «." 



The anterior part is a large fan-shaped muscle, the outer parts 

 of which are lost in the loose skin of the groin. The two posterior 

 parts are ribbon-shaped and fairly stout. The part " ft " does not 

 tally with any part of the rectus abdominis described by Gadow*, 

 but I think it must be regarded as forming part of this muscle- 

 sheet. 



Ohliquus abdominis intermits (text-figs. 57 & 67. 73). — Origin : 

 from the plastron close outside the lateral part of the origin of the 

 anterior rectus abdominis, and from the loose skin of the groin. 

 Its fibres run inwards and forwards dorsal to the thigh and are 

 inserted upon the dorsal posterior border of the lateral horn of 

 the pubis. 



Transversus abdominis (74). — A very small muscle-sheet lying 

 between the lateral parts of the obliquus internus and the perito- 



* Gadow : " Uuteisuchungen iiber die Bauchmuskeln dei- Kvokodile, Eidechsen 

 und Schildkroten," Morph. Jabrb. Bd. vii. (1882) p. 57. 



