38 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 
45. R. productus Ayres. 
“ The anterior nasal valve is dilated into a very narrow lateral fold, 
scarcely projecting beyond the nasal margin. The length of the nostril 
is slightly more than its distance from the lateral margin of the head 
and more than the distance between the inner angles of the nostrils, and 
much less than the width of the mouth, which is very slightly arched. 
Snout produced, the distance between the outer angles of the nostrils 
being f of that between the mouth and the end of the snout. A series 
of small, depressed, polished spines along the median ridge of the back ; 
groui)s of small, polished tubercles on the orbital margin and on the 
shoulder. A broad groove between the rostral ridges, which are sepa- 
rated along their entire length. Snout lighter colored than the rest of 
the body.” — {Streets.) Coast of California and southward. 
(Ayres MSS.; Girard, Proc. Ac. Nat. Sci. Phila. 1854, 196; Streets, Bull. U. S. Nat. 
Mils, vii, 1877, 55: lihinohaius leucorkynchus Giiutlier, viii, 444.) 
Super-family TOIIPEDINOIDEA. 
{The Torpedinoid Rays.) 
Family XIX.— TORPEDINID^. 
{The JTumh-Jishes.) 
Rays with the trunk broad and smooth j the tail comparatively short 
and thick, with rayed caudal fin, and commonly two rayed dorsal fins 
the first of which is over or behind the ventrals ; a longitudinal fold on each 
side of tail ; anterior nasal valves confluent into a quadrangular lobe j 
an electric organ composed of hexagonal tubes between the pectoral 
fins and the head. Genera 0 ; species about 15 ; large rays, noted for 
their power of giving electric shocks ; found in most seas. {Torpedinidce 
Gunther, viii, 448-455.) 
Dorsal tins two ; venti’als separate ; spiracles well behind the eyes Torpedo, 36. 
36.— TORPEDO Dnmdril, 1806. 
Eteetrie Bays. 
(Dum^ril, Zool. Analyt. p. 102: type Raia torpedo L.) 
Electric rays with the disk very broad, abrui)tly contracted at the 
tail ; two dorsal lins ; caudal fin well developed ; ventral fins lorge, sepa- 
rate; spiracles large, placed behind the eyes; mouth small; teeth iminted; 
skin jierfectly smooth. Large rays, chiefly inhabiting the Atlantic. 
