154 BULLETIN 95, UNITED STATES NATIONAL MUSEUM. 



front 6 in number ; incisors with truncate cutting edge ; behind these 

 in each jaw two small canine-like teeth; nostrils small, on level with 

 upper margin of orbit ; anterior with a flap, prolonged on posterior 

 side into a fringed tentacle; subopercle projecting backward, ending 

 in a spine, covered with skin ; head and body scaleless, covered with a 

 leathery skin; distance from tip of snout to origin of dorsal 1.45 in 

 standard length; longest dorsal ray 3.8 in head; caudal truncate, 

 membranes between rays deeply incised ; origin of anal under seventh 

 dorsal ray, the distance from tip of snout to origin of anal 1.27 in 

 standard length; vent anterior in position, separated from anal fin 

 by a distance equal to interorbital space; ventrals in front of pec- 

 torals and connected with them ; pectorals broad, posterior border 

 convex ; disk large, subcircular, longer than broad, its length 1.08 in 

 head and its breadth 1.31. 



Color in spirits, coppery red to flesh-color, back crossed by six 

 broad, dark reddish crossbands, the first on nape; second behind 

 pectorals ; third in front of dorsal ; fourth on base of dorsal ; fifth on 

 middle of caudal peduncle and sixth in front of base of caudal ; fins 

 yelloAvish, punctulate with dusky. This description is based on a 

 specimen 11.5 cm. long. 



The fin formula of these specimens is somewhat variable; one has 

 D. 8 ; A. 5 ; another D. 8 ; A. 6 and four have D. 9 ; A. 6. 



The following excellent description of the structure of the disk 

 by Giinther applies to these specimens : 



The whole disk is exceedingly large, subcircular, longer than broad, 

 its length being one-third of the whole length of the fish. The cen- 

 tral portion is formed merely by skin, which is separated from the 

 pelvic or pubic bones by several layers of muscle. The peripheric 

 portion is divided into an anterior and posterior part, by a deep 

 notch behind the ventrals. The anterior peripheric portion is formed 

 by the four ventral rays, the membrane between them, and a broad 

 fringe which extends anteriorly from one ventral to the other; this 

 fringe is a fold of skin, containing on each side the rudimentary 

 ventral spine, but no cartilage. The posterior peripheric portion is 

 suspended on each side on the caracoid, the upper bone of which is 

 exceedingly broad, becoming a free, movable plate behind the pec- 

 toral. A broad cartilage is firmly attached to it. The lower bone of 

 the coracoid is of a triangular form, and supports a very broad fold 

 of the skin, extending from one side to the other, and containing a 

 cartilage which runs through the whole of that fold. Five processes 

 of the cartilage are continued into the soft striated margin in which 

 the disk terminates posteriorly. The surface of the disk is coated 

 with thick epidermis, like the sole of the foot of higher animals. The 

 epidermis is divided into many polygonal plates; there are no such 

 plates between the roots of the ventral fins. ( Giinther. ) 



