NORTH PACIFIC OPHIURANS IN NATIONAL MUSEUM CLARK. 189 



large, about three on a side and one at apex of jaw; long, flat, and 

 more or less pointed; outermost somewhat the largest. First under 

 arm plate hexagonal, much wider than long; second plate some- 

 what triangular, barely in contact mth the first, wider than long; 

 succeeding plates separated, much wider than long, nearly tetragonal, 

 but the sides are not straight ; proximal margin \vith a slight median 

 point and distal, with a shallow median notch. Side arm plates larf^e, 

 meeting below but hardly above on basal part of arm; each plate 

 carries eight sharp, slender spines, of winch the upper ones are smooth, 



Fig. ,s7. - oi'iiioMiTiiA cddonomoki-ha. x 4. a, from abovk; ?), fkom below; c, .sii>k view of two 



AHM JOINTS NEAK DISK. 



the others (except the lowest) being rough or tliorny; the next to the 

 uppermost is longest, considerably exceetling the joint. Tentacle 

 scale single ; on first arm pore the scale is rounded oval and relatively 

 enormous, but the succeeding scales are much smaller antl are soon 

 narrow and pointed. Color (dried from alcohol), light gray. 



Locality. — AWatross station 4979, ofT eastern Japan, lat. 33° 53' N.; 

 long. 137° 42' E., 943 fathoms, brown mud, fine sand, foraminifera, 

 bottom temperature 36.4°, 1 specimen. 



T)fpe.— Cat. No. 25603, U.S.N.M., from station 4979. 



