NORTH PACIFIC OPHIURANS IN NATIONAL MUSEUM CLARK. 205 



arm plate wider than long, in contact with second, which is corre- 

 spondingly heptagonal; succeeding plates hexagonal, separated, at 

 first wider than long but rapidly becoming longer than wide; at 

 middle of arm the under arm plates are so encroached on by the huge 

 tentacle scales that their length may be nearly twice their least 

 breadth. Side arm plates large, meeting both above and below; 

 each plate carries about nine (seven to eleven in different specimens) 

 long, smooth spines, of which the second or third (from above) is 

 the longest, and may equal four joints. Tentacle scale single, very 

 large, often as long as the under arm plate, or nearly so, more or less 

 pointed. Color (dried from alcohol), very light brown. 



FIG. 9.5. OPHIACANTHA ANCHILABRA. x C. a, FROM ABOVE; 6, FROM BELOW; c , SIDE VIEW OF TWO 



ARM JOINTS NEAR DISK. 



Localities. Albatross station 4971, off eastern Japan, lat. 33 23' 30" 

 N.; long. 135 34' E., 649 fathoms, brown-green mud, foraminifera, 

 bottom temperature 38.1, 1 specimen; station 5084, off Omai Saki 

 Light, lat. 34 N. ; long. 137 49' 40" E., 918 fathoms, green mud, fine 

 sand, globigeriiia, bottom temperature 36.8, 5 specimens. 



Type. Cat. No. 25654, U.S.N.M., from station 5084. 



Although this species is nearly related to pcntagona and its allies, 

 it is easily distinguished from that group by its much broader and 

 stouter arms, and its longer and thicker oral papillae ; the long under 



