RECENT OPHIURANS. 173 



35. O. DISACANTHUS, sp. nov, {Sis, twice + iiKavea., spine). Plate 2, f. 3, 4. 



Disk 13 mm. in diameter; arms about 40 mm. long. Similar to purpureus 

 but differing in the number and arrangement of the oral papillae and in the 

 number of arm-spines. The oral papillae are seven on each side of the jaw, 

 sUghtly flattened, narrow, and pointed; the distal are larger than the proximal, 

 except that the pair at the apex of the jaw are the largest of all. Two or three 

 additional and similar papillae or scales occur on the outer margin of the second 

 oral tentacle-pore, so that there appears to be a series of about ten close-set 

 oral papillae in a single row along each side of the jaw. This species is therefore 

 more hke tropicus as regards the oral papillae than it is like any other species 

 of the genus. The arm-spines are not at all glassy nor are they skin-covered; 

 they are smooth, slightly tapering but blunt, subequal and a httle longer than 

 an arm-joint. On the basal ten or a dozen joints there are three spines on each 

 side, but elsewhere there are only two (hence the name). No other species 

 of Ophioscolex has two spines to a joint, except at the very tip of the arm. 

 The color of this specimen, dried from alcohol, is light yellow-brown. 



HoLOTYPE (M. C. Z. 2159). Off western Cuba, 190 fms. Blake St. 23. 



Mr. Lyman (1878. Bull. M. C. Z., 5, p. 233) refers two specimens, taken 

 at this station, to 0. purpureus and says he "could see no specific difference on 

 comparing originals from Scandinavia," but in a note left with the only speci- 

 men now in the collection he calls attention to the "better marked" oral 

 papillae. He evidently did not notice the highly characteristic number and 

 arrangement of the arm-spines. 



36. 0. GLACIALIS Muller and Troschel, 1842. Syst. Ast., p. 109. 



20 specimens. Franz Josef Land, 125 fms. Spitzbergen: Ice Fjord, 

 134 fms. Norway 1; Lofoden, 200-300 fms. Sweden: Bohusia; Bohuslan. 

 Off Newport, R. I., 192 fms. Off Charleston, S. C, 75 fms. Off Dominica, 

 333 fms. Off Barbados, 100-209 fms. 



37. O. PURPUREUS Duben and Koken, 1846. Kongl. Vet.-akad. Handl. t. 1844, p. 235, pi. 6, f. 



2a-2c. 



9 specunens. Norway^: Lofoden, 200-300 fms.; Bodo, 80-100 fms. 

 Between Cape Wrath, Scotland and the Faroe Islands. 



38. O. STIMPSONU Lyman, 1875. Illus. cat. M. C. Z., no. 8, pt. 2, p. 23, pi. 1, f. 11-15. 



HoLOTYPE and 4 PARATTPES. Florida: off Sombrero Key, 240 fms. 



' Without definite locality. 



