76 Bulletin 4.7, United States National Museum. 



surface sparsely and evenly covered with small sharp prickles with stellate 

 base, crowded between eyes, in a broad band along front of disk, behind 

 shoulders and especially on sides of tail ; no spines on orbital rim or shoul- 

 ders ; a small spine on middle of back between shoulders ; 23 spines along 

 median line of tail. Anterior outline strongly undulated, convex near 

 tip of snout, which slightly projects. Length of disk \\ in its width ; 

 interorbital space concave, \\ times eye, which is 3| in snout. Distance 

 from front of eye to edge of disk, If in snout. Tail longer than body by 

 \ snout; dorsals small, equal, prickly. Color plum color, darker at 

 margin ; brownish below, becoming dark on fins. L. 18 inches. One speci- 

 men known from Santa Barbara Channel, in 822 fathoms. (Gilbert.) 

 (rpaxvc rough ; ovpd tail.) 

 Raia trachura, GILBERT, Proc. U. S. Nat. Mus., 1891, 539, Santa Barbara. 



109. RAJA ABYSSICOLA, Gilbert & Thoburn. 



Three strong spines on middle of back and a series down median line of 

 tail. No other spines present. A band of enlarged prickles on each side 

 of tail. Both upper and lower surface hispid with close-set, slender 

 bristles; the margins of disk, the ventrals, and the under surface of tail 

 partly naked. No scapular spines. Anterior margin of disk concave 

 near snout and near pectoral angle, a convex area intervening. Snout 

 broad, but not short nor blunt. Interorbital space deeply concave. 

 Claspers long, slender and flexible. Rostral cartilage imperfect ; skeleton 

 generally very flexible. Hooks on pectorals in male imperfectly devel- 

 oped. Nearly uniform sooty brown on both upper and lower sides, with 

 a few scattered black spots above. 



A single specimen known, a male 45 inches long, taken off the Queen 

 Charlotte Islands, British Columbia, at a depth of 1,588 fathoms, the 

 greatest depth at which a ray has been found. A strongly marked spe- 

 cies, probably type of a distinct genus, (abyssicola, living in the depths:) 



Raja abyssicola, GILBERT & THOBURN, Bnll. U. S. Fish Com., 1894, Queen Charlotte Islands* 



Family XXV. NARCOBATID.E. 

 (THE ELECTRIC RAYS.; 



Trunk broad and thick, covered with perfectly smooth skin. Tail com- 

 paratively short and thick, with rayed caudal fin, and commonly 2 

 rayed dorsal fins, the first of which is over or behind the ventrals ; a longi- 

 tudinal fold on each side of the tail ; anterior or nasal valves confluent 

 into a quadrangular lobe; a large electric organ composed of many hex- 

 agonal tubes between the pectoral fins and the head. Genera 7 ; species 

 about 15 ; rays of moderate or large size, noted for their power of giving 

 electric shocks ; found in most warm seas. According to Fritsch, the tor- 

 pedoes pass through 3 distinct phases of development, a shark-like, a 

 ray-like, and finally a torpedo-like stage. The very young have long 

 external gills. (TORPEDINID^E, Giinther, Cat., vin, 448-455.) 



a. Dorsal fins 2. 



b. Ventral fins separate, tail moderate. 



c. Spiracles at some distance behind the eyes. 



