OPHIUROIDEA OF THE BAHAMA EXPEDITION. 47 



the first is very small, quadrant-shaped. One large, flat, 

 elliptical or broad-ovate tentacle-scale, nearly as long as the 

 under arm-plate, and usually a minute one in front of it. In a 

 few cases the first tentacle-scale is bifid. 



The arm-spines are about six, and are unusually short and 

 smooth for this genus. Their length is about equal to the 

 breadth of the under arm-plates. They are not very unequal; 

 the lower ones are usually the largest; most of them are trun- 

 cate or blunt, distinctly flattened, tapered, and curved back- 

 ward; the lower ones are usually more tapered, nearly straight, 

 subacute. They are dull and opaque, not thorn)- nor ser- 

 rate, but microscopically roughened. 



The proximal upper arm-plates are broadly in contact, 

 broader than long, six-sided or subtrapezoidal, with the inner 

 end truncate; the outer end, which is broadly convex or sub- 

 truncate with a median sinuosity, is much the widest. Dist- 

 ally they become relatively narrower and more nearly tri- 

 angular, with rounded angles. 



Color, in alcohol, light buff. 



The larger specimens have a disk 11 mm. across; the arms 

 are all broken. 



Station 13, off Havana, in 200 fathoms, three examples. 



Ophiopristis VerrilL (See p. 39.) 



Ophiopristis ensifera Ver., sp. nov. 



Plate IV; Figures i — id. 



Arms five, long and slender, with flat serrate spines. Disk 

 flat, slightly ten-lobed, covered thickly, except on a part of 

 the radial shields, with small obtuse and conical granules, 

 mixed in some parts with minute, sharply conical spinules; all 

 gradations in form, from the rounded granules to the conical 

 spinules occur. Where the granules are partly rubbed off, 

 in dry specimens, the surface is covered with small, distinct, 

 imbricated scales. The radial shields are small; the naked 



