234 



BULLETIN 75, UNITED STATES NATIONAL MUSEUM. 



plates moderate, meeting both above and below; each i)late carries 

 half a dozen slender, sharp spines, the uppermost longest and exceed- 

 ing three joints; the two upper spines are smooth but the lower ones 

 are rough near the tip. Tentacle scales single, small, spiniform, and 

 sharp. Color (dried from alcohol), whitish, yellowish, or grayish. . 



Localities. — Albatross station 2859, off Alaska, lat. 55° 20' N.; long. 

 136° 20' W., 1,569 fathoms, gray ooze, bottom temperature 34.9°, 183 

 specimens; station 2860, off British Columbia, lat. 51° 23' N.; long. 

 130° 34' W., 876 fathoms, green mud, bottom temperature 36.5°, 

 11 specimens; station 3603, Bering Sea, lat. 55° 23' N.; long. 170° 

 31' W., 1,771 fathoms, brown ooze, bottom temperature 35.1°, 3 



specimens; station 





4761, off Shumagin Is- 

 lands, lat. 53° 57' 30" 

 N.; long. 159° 31' W., 

 1 ,973 fathoms, blue 

 clay, bottom tempera 

 ture 35°, 14 specimens; 

 station 4766, Bering 

 Sea, lat. 52° 38' N.; 

 long. 174° 49' W., 1,766 

 fathoms, character of 

 bottom and bottom 

 temperature not ob- 

 served, 117 specimens. 

 Bathymetrical range, 

 876 to 1,973. fathoms. 

 Temperature range, 

 36.5° to 34.9°. Three 

 hundred and twenty- 

 eight specimens. 



Type.—C at. No. 

 25541, U.S.N.M., from 

 station 2859. 



Although this species has no very distinctive marks, it appears to 

 be different from any other known member of Ophiacanthi. The 

 form and position of the adoral plates are unfortunately not abso- 

 lutely reliable characters, but taken in connection with others may 

 be useful. The disk covering, the upper arm plates, the arm spines, 

 and the tentacle scales are the most important characters in that 

 connection. The species seems to be a typically abyssal ophiuran 

 and it is rather remarkable that it is so little differentiated from more 

 shallow-water species. 



Fig. 110.— Ophiacantha bathybia. X 4. a, from above; h, 

 FROM below; c, side view of two arm joints near disk. 



