XVII 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 
Fic. 265.—The Electric Ray (Torpedo ocellata). Dorsal (A) and ventral (B) views. 
pf, Pectoral tin ; 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 Yorpedo (Fig. 265) is represented by 
species in the Mediterranean (7. marmorata, T. narce, T. hebetans), 
the Red Sea, and the Atlantic and Pacific Oceans. 7. hebetans 
