HIND-LIMB. 137 



Hind-limb. 



C. 173. The muscles of the right pelvic fin of a Dog-fish 

 (Scyllium catulus}. The deep and superficial muscle-layers 

 on both surfaces of the fin are inserted into the horny fin- 

 rays. On the ventral surface they are only recognizable as 

 distinct layers by the different direction of their fibres. 

 Those of the superficial sheet rise from the pelvis and 

 median tendinous septum and run directly to the rays ; 

 while those of the deeper layer are interrupted in their 

 course by the basal pterygia. On the dorsal surface the 

 layers are more distinct; the superficial rises from the 

 general aponeurotic sheath of the trunk, and runs in well- 

 defined bundles to the fin-rays (a deeper slip of this muscle 

 (A) is attached to the base of the clasper). The deep layer 

 rises from the basal pterygia. 



Davidoff, Morph. Jahrb., Bd. v. 1879, p. 454. 



C. 174. Right pelvic fin of a Sea-Cat (Chimcem monslrosa], 

 showing the muscles. Upon the ventral surface the layers 

 are simple in character and not very clearly defined, but 

 upon the dorsum the superficial sheet shows marked indi- 

 cations of subdivision into three independent muscles 

 (superf. A, B, C). The anterior part of superf. A, from 

 its position, would act as a protractor of the fin. 

 Davidoff, Morph. Jahrb., Bd. v. 1879, p. 473. 



C. 175. Right pelvic fin of a Cod (Gadus m or r hit a], showing 

 the muscles. The superficial layer (Su) on both surfaces of 

 the fin is divided into several well marked muscles, which, 

 according to their position, act as dilators, approximators, 

 levators, or depressors. The deep layer (Pf) on both 

 surfaces is simple. All the muscles are attached to the 

 base of the fin-rays. 



C. 176. The hind limbs of a Hell-bender (Cryptobranclms alleglian- 

 iensis), showing the superficial muscles in the upper speci- 

 men, the deep muscles in the lower. The arrangement of the 

 muscles in simple superficial and deep layers is more strongly 

 marked than in the fore-limb ; it can best be seen in the 

 muscles on the inner surface of the thigh. The following are 

 the names of the individual muscles (indicated by numbers 



