NORTH PACIFIC OPHlURANS IN NATIONAL MUSEUM CLARK. 135 



within. Oral papillae single, at outer corner of mouth angle, very 

 large, flat, and wing-shaped. Teeth minutely notched. Genital 

 slits narrow. First under arm plate very small, tetragonal, about as 

 wide as long; second, much larger, somewhat pentagonal; succeeding 

 plates tetragonal, becoming wider than long; first and second in con- 

 tact, but succeeding plates hardly touch each other, though they 

 separate the side arm plates widely. Latter rat her large, not meeting 

 either above or below at base of arm, but soon touching and meeting 

 broadly at tip ; each plate carries three arm spines, of which the upper- 

 most is about twice as long as lowest, which is equal to an arm joint. 

 Tentacle scales single, very large, oval. Color (dried from alcohol), 

 disk, pale gray; upper side of arms, pink; arm spines and lower surface, 

 whitish. 



Localities. Albatross station 4810, Sea of Japan, lat. 41 17' 20" 

 N. ; long. 140 7' E., 195 fathoms, fine gray sand, bottom temperature 

 44.7, 1 specimen; station 4965, off eastern Japan, lat. 33 35' 20" X. : 

 long. 135 10' 50" E., 191 fathoms, dark green-gray sand, shells, bottom 

 temperature 49.4, 6 specimens; station 4967, off eastern Japan, lat. 

 33 25' 10" N. ; long. 135 37' 20" E., 244 to 253 fathoms, brown mud, 

 sand, foraminifera, bottom temperature 45.9, 1 specimen. Bathy- 

 metrical range, 191 to 253 fathoms. Temperature range 49.4 to 

 44.7. Eight specimens. 



Type. Cat. No. 25640, U.S.N.M., from station 4965. 



Although there are several indications besides the size and the 

 presence of six arms that the specimens from station 4965 are young, 

 the individual from 4967 measures 6 mm. across the disk, and is quite 

 probably mature, yet it does not differ in any important particular 

 from the others, except that the upper arm spine is not equal to two 

 joints and the color is uniformly whitish. In any case, the very large 

 oral papillae, the six arms, the long arm spines and the peculiar upper 

 arm plates combine to give a very characteristic appearance, and I 

 know of no species to which the specimens could be referred. The 

 one from station 4810 is, however, so small (disk diameter less than 3 

 mm.) that its identity is bound to be somewhat uncertain. 



OPHIACTIS BRACHYGENYS, new species." 



Disk 5 mm. in diameter; arms about 25 mm. long. Disk covered 

 with about two hundred scales of diverse sizes and indefinite arrange- 

 ment. Radial shields long and narrow, separated except at their 

 distal ends. Arms five, broad at base, but slender at tip. Upper 

 arm plates transverse, elliptical, or low triangular, with rounded an- 

 gles, scarcely in contact even at base of arm. Interbrachial spaces 

 below completely covered with fine scales. Oral shields low, trian- 



a Bpa%i>c, signifying short, and fsvuf, signifying jaw, in reference to the small mouth 

 angles. 



