ELASMOBRANCHII BATOIDEI 



463 



in the centre by a branched prenasal rostrum, and laterally by 

 the curiously branched preorbital cartilages, each of which 

 radiates outwards and forwards from a common basal articulation 

 with the lateral ethmoid regions of the skull. Tail relatively 

 short and thick, with two dorsal fins, a caudal fin, and two 

 lateral longitudinal folds. Skin smooth, without denticles. 

 Mouth transverse and ventral. A characteristic quadrangular 



FIG. 265. The Electric Ray (Torpedo ocdlata). Dorsal (A) and ventral (B) views. 

 p.f. Pectoral fin ; pv.f, pelvic fin ; sp, spiracle. 



naso-frontal lobe, with a free hinder margin, which forms the 

 anterior lip, is enclosed by the two nasal organs and the oro- 

 nasal grooves leading from them to the corresponding angles of 

 the mouth. A pair of large electric organs between the pectoral 

 fins and the head. Seven genera and about fifteen species. 

 Inhabitants of most warm seas. 



The well-known genus 'Torpedo (Fig. 265) is represented by 

 species in the Mediterranean (T. marmorata, T. narce, T. liebetans), 

 the Eed Sea, and the Atlantic and Pacific Oceans. T. liebetans 



