HIND-LIMB. 153 



has great powers of flexion and extension. Adduction of 

 the toes, to minimise the resistance of the water during the 

 recovery, is effected by a slight modification of the extensor 

 longus digitorum tendon. The division of the tendon 

 occurs so far down the foot, that the branches are set at a 

 wide angle and upon traction draw the toes together. The 

 tensor fasciae latse is continuous with the obliquus 

 externus abdominis. The adductors are absent or perhaps 

 fused with the large obturator externus. The biceps is 

 formed of two distinct parts, one of which (short head) 

 rises from the sacral vertebrae, the other (long head) from 

 the tuber ischii. The latter is attached along the whole 

 outer border of the fibula and acts as an outer rotator. 

 Tho peculiar arrangement of semitendinosus and semi- 

 membranosus makes it difficult to decide their homologies 

 with any certainty. The soleus is absent. 



C. 222. A similar specimen of the deep muscles of the left hind- 

 limb. The peroneus longus is attached partly to the 

 external condyle of the femur. The short extensors rise 

 from the dorsum of the foot with the exception of that to 

 V. (peroneus quinti dig.). 



Miller, Challenger Reports (Zool.), vol. xxvi. 1888, 

 p. 176; Lucse, Abhandl. Seckenberg. Natur. Gesellsch., 

 Bd. ix. 1873-75, p. 448. 



C. 223. Distal portion of the right hind-limb of a Dog (Canis 

 familiaris), showing the muscles of the shank and foot. 

 The plantaris is of great size and is fused at its origin with 

 the outer head of the gastrocnemius. The main tendons of 

 the flexor tibialis and flexor fibularis are united in the sole 

 of the foot. An extensor brevis digitorum v. (peroneus 

 quinti) is present, rising as usual from the proximal part 

 of the fibula. The short extensors n., ill., IV. are well- 

 developed and rise from the dorsum of the foot. The 

 tibialis posticus, extensor hallucis, and flexor tibialis, owing 

 apparently to the absence of the hallux, are all more or 

 less rudimentary. The soleus is absent. 0. C. 64 z q b. 



Presented by Prof. McFadyean. 



