NORTH PACIFIC OPHIURANS IN NATIONAL MUSEUM CLARK. 201 



OPHIACANTHA RHACHOPHORA, new species.a 



This species is so close to the two preceding that a detailed descrip- 

 tion would be quite superfluous. Its only specific peculiarities lie 

 in the very rough arm spines (except the uppermost), tentacle 

 scales, and even oral papillae. In extreme cases the tips of the distal 

 oral papillae bear several teeth or little thorns, and the tentacle 

 scales are sharp pointed with a thorn or two on each side. Other 

 specimens have these peculiarities less marked and approach very 

 near to pentagona, and I do not feel sure that rhachophora is anything 

 more than a slight variety of that species. For the present, how- 

 ever, I think it well to 

 distinguish it by a sepa- 

 rate name. 



Localities . A Tbatross 

 station 3698, off Mana- 

 zuru Zaki, Honshu Is- 

 land, Japan, 153 fathoms, 

 green mud, volcanic 

 ashes, sand, 1 specimen; 

 station 3717, off Ose 

 Zaki, Honshu Island, Ja- 

 pan, 63 to 100 fathoms, 

 volcanic sand, shells, 

 rocks, 2 specimens; sta- 

 tion 3750, off Suno Saki, 

 Honshu Island, Japan, 

 83 to 140 fathoms, gray 

 sand, broken shells, peb- 

 bles, 1 specimen; station 

 4771, Bering Sea, lat. 

 5430 / N.; long. 179 17' 

 E., 426 fathoms, broken 

 shells, bottom tempera- 



ture 38.1 2 specimens' FIG. 92. OPHIACANTHA RHACHOPHORA. X 8. a, FROM ABOVE; b, 



FROM BELOW; c. SIDE VIEW OF TWO ARM JOINTS NEAR DISK. 



station 4772, Bering Sea, 



lat. 54 30' 30" N.; long. 179 14' E., 344 to 372 fathoms, green- 

 brown sand, 1 specimen; station 4775, Bering Sea, lat. 54 33' 30" 

 N.; long. 178 44' E., 584 fathoms, green mud, black specks, 

 foraminifera, bottom temperature 37.2, 16 specimens; station 

 4809, Sea of Japan, lat. 41 36' 12" N.; long. 140 8' 40" E., 90 to 

 207 fathoms, gray sand, pebbles, broken shells, 12 specimens; sta- 

 tion 4893, Eastern Sea, lat. 32 32' N.; long. 128 32' 50" E., 95 to 

 106 fathoms, gray sand, broken shells, pebbles, bottom tempera- 



, signifying a briar, and <f>opa, signifying a carrying, in reference to the very 

 thorny arm spines and tentacle scales. 



