158 BULLETIN OF THE 



through -which may he distinguished the upper side of the arm-hones. Disk 

 flat and thin, covered with a thick, slightly wrinkled skin, which conceals the 

 radial shields and the fine scaling, though the latter may he distinguished in 

 the lower interhrachial spaces. Genital scales quite hidden. Genital opening 

 extending from the mouth-shield to the margin of the disk. Three cylindrical, 

 stout, nearly equal, pointed arm-spines, about as long as an arm-joint. One 

 small rounded tentacle-scale on iimer side of the tentacle-pore. Color in alco- 

 hol, gray. 



I admit this species to Ophioscolex with some hesitation. The mouth-papillse 

 are different in shape and arrangement ; but the absence of upper arm-plates 

 and the characteristic covering of smooth skin suggest its position. 



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



OPHIOLEBES* gen. nov. 



Disk and arms stout, and covered by a thick skin, which bears grains or 

 stumi^s, and hides more or less the underlying plates. Arm-spines short, 

 blunt, thorny, covered by thick skin, and arranged on the sides of the side arm- 

 plates, which project but slightly. Long stout mouth-papillae, and teeth ; no 

 tooth-papillae. Jaw-covers large and wide, making a circle by their connecting 

 ends.t Arm-plates rather small, but normal, nearly as in Ophiacantha. Two 

 genital openings in each interhrachial space. 



Ophiohhes includes Ljungman's Ophiactis davigera, besides the two species 

 here described. 



Ophiolebes seorteus sp. nov. 



Plate VII. Figs. 196, 197. 



Special Marks. — Four short blunt arm-spines covered with thick skin, the 

 upper one longest. Five feeble mouth-papillse to each angle. Radial shields 

 like ridges and set with grains. 



Description of an Individual (Station 145). — Diameter of disk 7.5 mm. 

 Length of arm about 23 mm. Width of arm close to disk, without spines, 

 1.5 mm. There may be seen on each angle the outlines of five small mouth- 

 papillae, two widely separated on the sides and one longer and more slender at 

 the apex, all covered by a thick skin, which, when removed, shows them as 

 long, cylindrical, and stout. The mouth-shields, whose outlines may be vaguely 

 seen, are small triangular, ■\\-ith an angle inward and outer edge curved. Side 

 mouth-shields hidden by skin, which, when removed, shows them long and 

 narrow, meeting within, and nearly or quite joining without, between first and 

 second arm-plates, so as to form a continuous line about the mouth. First 

 under arm-plate diamond-shape ; the rest are pentagonal, with an angle inward 



* 6<t>Li, snake ; X^^t/i, basin. 



t 'The jnw-covcr is the internal plate wliich roofs over the open angle above each 

 pair of mouth-frames in the interhrachial space. 



