128 BULLETIN OF THE 



■blunt-pointed arm-spines, the upper one longer, and two thirds as long as an 

 arm-joint. One large round tentacle-scale on each pore. Color in alcohol, 

 white. 



Station 23, 450 fathoms, 1 specimen. 



Ophiozona depressa sp. dot. 



Plate VI. Figs. 155 - 157. 



Special Marks. — Two nearly equal short arm-spines. Arm low. Side 

 arm-plates slightly flaring without. Eadial shields large, oval, and widely 

 separated. 



Description of an Individual (Station 214). — Diameter of disk 11 mm. 

 Length of arm about 37 mm. Width of arm close to disk, without spines, 

 1.8 mm. Four short, squarish, close-set mouth-papilloe on each side, the 

 outer one very small, and a pair somewhat more pointed at apex of angle. 

 Mouth-shields longer than broad, with a shai-p angle within, and outer side 

 bo'unded by a deep curve ; length to breadth 2 : 1.7. Side mouth-shields 

 short, broad without, tapering inward, where they meet in a point. First un- 

 der arm-plate very small, transverse pointed oval ; next two plates long pen- 

 tagonal, with a truncated angle within, deep re-entering curve on each inner 

 lateral corner, and a curved outer edge ; beyond these the plates are short 

 pentagonal. Side arm-plates low (the arm being flat), little swollen, slightly 

 flaring outward, meeting below beyond the fifth under arm-plate, and above 

 Ijeyond the second upper plate, which is fan-shaped, with an angle within. 

 Disk round and flat ; in the centre is a large pentagonal primary plate, round 

 which are five others, smaller and more or less rounded, separated from each 

 other by a triangular scale. These primary plates have a little central boss or 

 tubercle ; in the interbrachial spaces is a radiating row of three large elongated 

 plates, the outer and longest being marginal. Radial shields flat, longer than 

 broad, oval, separated their entire length by two large plates ; length to 

 breadth 2.5 : 1.7 mm. Lower interbrachial space filled by irregular trans- 

 verse rows of uneven plates, the outer row long and angular. Genital scales 

 long, narrow, and broken in several pieces. Genital opening not extending to 

 margin of disk. Two short, blunt, tapering arm-spines of equal length, and 

 about half as long as an arm-joint. One large rounded tentacle-scale on the 

 inner side of each tentacle-pore. Color in alcohol, white. 



Station 214, 500 fathoms, 3 specimens. 



Ophiozona nivea Ltm. 

 Ophiozona nivca, 111. Catal. Mus. Comp. Zool. VIII. No. 2, p. 9, Figs. 85, 86. 1875. 

 Station 24, off St. Thomas, 390 fathoms, 1 specimen. 



