102 BULLETIN OF THE 



Ophiocten pallidum sp. nov. 



Plate V. Figs. 126-138. 



Special Maries. — Disk covered with minute thin scales, among which appear 

 very small, widely separated primary plates. One minute tentacle-scale. Three 

 short, equal, slender arm-spines. 



Description of an Individual (Station 160). — Diameter of disk 14.5 mm. 

 Length of arm about 70 mm. Width of arm close to disk, without spines, 1.7 mm. 

 Five short, blunt, ill-defined mouth-papilla3 on the side, and one larger at apex 

 of jaw, like the three or four teeth that stand immediately above it. IMouth- 

 shields much broader than long, bounded on the outer edge by a wide curve and 

 by a very wide angle within ; length to breadth 1.2 : 2.6. Side mouth-shields 

 long and narrow, extending along the inner angle of the mouth-shield, and just 

 meeting within, where they broaden slightly, becoming narrower at the outer end 

 ■where attached to the side arm-plate. First under arm -plate much larger than 

 the others, four-sided, with outer edge straight, lateral sides re-enteringly curved, 

 and a short side, like a truncated angle within ; the rest of the under arm-plates 

 are very small, with a curved outer side, and are nearly semicirciilar in form, 

 but have a slight peak inward at the junction of the side arm-plates, which 

 are thin and wide, flaring slightly outward, meeting broadly below, and separated 

 above by the upper arm-plates, which are four-sided, with outer edge nearly 

 straight and wider than inner. Disk round, smooth, and flat, covered with 

 minute, very thin, overlapping scales, four or five in the length of a mm. on 

 upper surface, and more below ; among them may be distinguished small, 

 round, widely separated primary plates. Radial shields longer than broad, 

 three-sided, with all three angles much rounded, widely separated their entire 

 length by the disk scaling ; length to breadth 2.6 : 1.5. Genital scales hidden, 

 except the outer tip, which shows outside the radial shield, and bears no papilla;, 

 or only one or two rudimentary. Three sharp, slender, tapering arm-spines 

 situated close to each other on the middle edge of the side arm-plate. Only 

 one very minute, rounded tentacle-scale on the outer edge of some of the ten- 

 tacle-pores ; a little way out on the arm there usually is a minute scale on the 

 inside of the pore, and none on the outer side. Color in alcohol, pale straw. 



Station 160, 2600 fathoms, 12 + specimens. Station 156, 1975 fathoms, 

 4 specimens. 



Ophiocten sericeum? Ljn. 



Ophiura sericea Fbs. 



Ophiocten Krihjeri Ltk. 



Ophioglypha gracilis ? (young) G. O. Sars. 



Ophiocten sericeum seems not to differ essentially from Ophioghjjiha gracilis, 

 cxcejd in having a coml) of fine jiapilko along tlie outer edges of the basal upjier 

 arm-plates ; but this comb is wanting in the young, and not regular in the adult. 



