NORTH PACIFIC OPHIURANS IN NATIONAL MUSEUM - CLARK. 243 



wider than long. Adoral plates each about as large as oral shield, 

 roughly pentagonal, twice as long as wide; oral plates rather large. 

 Oral papillae, three on a side and one at apex of jaw, rather thick and 

 club-shaped. First under arm plate small, wider than long; second 

 plate somewhat triangular, nearly as long as wide; succeeding plates 

 more pentagonal or hexagonal, as long as wide or longer; all- -the 

 plates, except the first two, are well separated from each other. 

 Side arm plates large, meeting above and below; each plate carries 

 six stout arm spines, of which the uppermost is longest and exceeds 

 two joints; three lowest spines thickened and deeply notched (ver- 

 tically) at tip, so that each one ends in two or three blunt points. 

 Tentacle pores small; tentacle scales single, flat, smooth, rounded. 

 Color (dried from alcohol), dirty yellowish- white. 



Locality. Albatross station 4784, off Attu Island, lat. 52 55' 40''' 

 N.; long. 173 26' E., 135 fathoms, coarse pebbles, 1 specimen. 



Type.Csit No. 25737, U.S.N.M., from station 4784. 



This species is so unlike any of the preceding or any of the previ- 

 ously known species that it can not be confused with them, but it is 

 very near the following species (tylota), with which it was taken, and 

 more abundant material may show that it is not specifically distinct. 



OPHIOLEBES TYLOTA, new species.a 



Disk 10 mm. in diameter; arms about 40 mm. long. Disk covered 

 with coarse scales, many of which bear stout, blunt spines; these 

 spines are thickest near base and are sometimes imperfectly divided 

 or slightly branched. Radial shields triangular, in contact at inner 

 distal angle but widely separated within. Upper arm plates rhombic, 

 basal ones more or less rounded, about as long as wide, well separated 

 from each other. Interbrachial spaces below much like disk above. 

 Genital slits rather small. Oral shields rather small, rounded 

 rhombic, very much wider than long. Adoral plates nearly as large, 

 about twice as long as wide; oral plates well developed. Oral 

 papillae, three on a side and one at apex of jaw, long, thick, and blunt. 

 First under arm plate squarish; second plate much larger, some- 

 what pentagonal, longer than wide; succeeding plates rapidly becom- 

 ing wider than long, with distal margin curved and notched at the 

 middle; all plates except first two separated from each other, though 

 not always distinctly. Side arm plates large, meeting above, but not 

 below, at base of arm; each plate carries six stout arm spines, of 

 which the uppermost is longest and nearly equal to three joints; 

 lower ones rough at tip and sometimes thickened and slightly 

 notched. Tentacle pores moderate ; tentacle scale single, flat, some- 

 what elongated, smooth, rounded at tip. Color (dried from alaohol), 

 whitish, yellow, dirty brownish, or bright brown. 



, signifying knobbed, in reference to the thick disk spines and lowest 

 arm spines. 



