NOETH PACIFIC OPHIURANS IN NATIONAL MUSEUM CLARK. 



97 



1 specimen; station 5085, Sagami Bay, Japan, lat. 35° 6' 45" X.; 

 long. 139° 19' 45" E., 622 fathoms, green mud, fine black sand, bot- 

 tom temperature 37.8°, 3 specimens. Bathymetrical range, 501 to 

 876 fathoms. Temperature range, 38.1° to 36.5°. Sixty-three 

 specimens. 



These specimens have been compared with specimens from the 

 Panamic region identified by Liitken and Mortensen, and there seems 

 to be no reason to doubt their identity. The largest specimen is 14 

 mm. across the disk, the smallest only 6 mm. 



OPHIOCTEN CHARISCHEMA, new species.^ 



Disk 1 1 mm. in diameter; arms about 70 mm. long. Disk very flat, 

 thin, deeply notched at the base of the arms (radius, 5 mm. long, 

 interradius 6 mm.), covered with a coat of fine, unequal scales which 

 are normally completely concealed by a very dense covering of minute 



Fig. 35.— Ophiocten charischema. X5. a, from above; b, from below; c, side view of three arm 



JOINTS near disk. 



granules, several hundretl to a square millimeter. Radial shields also 

 completely hidden. Upper arm plates tetragonal, distal margin con- 

 vex, lateral margins divergent; basal plates much wider than long but 

 becoming longer than wide on terminal half of arm; all are broadly in 

 contact. There is no trace of an arm comb. Interbrachial spaces 

 below covered by a coat of about thirty scales, among which a few 

 minute granules are scattered. Oral shields quite variable in shape, 

 but commonly longer than wide; usually they are pentagonal, with 

 somewhat rounded angles, and the sides nearly equal, but sometimes 

 (as in fig. 356) the distal side is very short. Adoral and oral plates not 

 peculiar, save for bearing a few scattered granules. Oral papillae 

 numerous, about seven on a side. Genital slits and scales short, 

 without marginal papillae. First under arm plate somewhat octagonal, 

 about as long as wide; second plate more hexagonal, distal margin 

 longer than proximal; third and fourth plates more tetragonal, but 



a Xapisic, signifying pleasing, and a^^/ta (to), signifying /or/n, in reference to the 

 very graceful appearance. 



34916°— Bull. 75—11 7 



