RAJIFORMES 



163 



modified portion of the visceral muscles, and of totally different origin 

 from that of the Rajidae (Fritsch [141]). 



The Torpedinidae appear to be much more closely allied to the 

 Rajidae than to the Centrobatoidei. Yet there is reason to believe that 

 they should be derived independently from some Rhinobatid-like ancestor 



EO 



Tr 



FIG. 126. 



Torpedo with electric organ, E.O, and brain exposed ; dorsal view. On the right side only 

 the dorsal surface .of the organ is exposed ; on the left the nerves which supply it are shown. 

 Br, branchial sacs ; GR, sensory canals of lateral-line system ; Le, electric lobe of brain ; 0, eye ; 

 Tr, trigeminal nerve ; V, vagus nerve. (After Gegenbaur, from Sedgwick's /oology.) 



(Jaekel). Of living genera Narcine is perhaps the most primitive, and 

 Torpedo one. of the most specialised. 



Torpedo, Dum. ; Mediterranean, Atlantic, and Indian Ocean, to Eocene, 

 Europe. Hypnos, Dum. ; Australian. Narcine, Henle ; tropical seas, and 

 Eocene, Italy. Astrope, M. and H. ; Indian Ocean. Ternem, Gray ; 

 Indian seas. 



GROUP C. CENTROBATOIDEI. 



The rostral cartilage is usually lost, but the skeleton of the pec- 

 toral fins grows forward to meet in front of the skull (Fig. 119, B). 



