336 RECENT OPHIURANS. 



transverse row of 3 small triangular scales. (In the holotype, the 6 primary 

 plates are asymmetrically arranged and the same is true of several other speci- 

 mens). Radial shields rather large, united for their whole length, the pair 

 forming an almost perfect semicircle, distal to which the contiguous ends of 

 the genital scales project. Upper arm-plates wider than long, rounded triangular, 

 the proximal angle truncated on the basal joints where the plates are more or 

 less in contact; at the middle of the arm and distally they are fully separated. 

 Interbrachial areas below covered by 12-15 scales. Oral shields small, not so 

 large as one of the adoral plates; diamond-shape and longer than wide, or distal 

 angle truncated and then width and length about equal. Adoral plates very 

 large, narrower within than without but fully in contact with each other. Oral 

 plates very small. Oral papillae 3 on each side, a block-like infradental one, 

 a smaller flat scale on the edge of the oral plate and a large, flat scale twice as 

 wide as high, partly on the oral, and partly on the adoral, plate ; the median and 

 distal papillae close the oral slit, as in Amphiphohs. First under arm-plate 

 very small, nearly square; succeeding plates pentagonal (with proximal angle), 

 much wider than long, distally becoming minute and squarish; only two or 

 three basal ones are in contact. Side arm-plates rather large and projecting, 

 meeting both above and below except at base of arm; each one bears a vertical 

 series of slender, pointed arm-spines, 6 on the first joint outside the disk, then 5 

 on one or two joints, then 4 to the middle of the arm and 3 distally; the next 

 to the uppermost is longest and equals (at first) about a joint and a half, but at 

 the middle of the arm it hardly equals a joint. On the tentacle-pores of 3 or 4 

 basal joints, there is a single well-developed tentacle-scale, but beyond that there 

 are none, although the tentacles are evident clear to the tip of the arm. Color, 

 nearly white. 



Holotype (M. C. Z. 785) and 18 paratypes (M. C. Z. 832, 833, 3929). 

 Off Barbados, 76-103 fms. Blake Stations 272, 273 and 293. 



These specimens are labeled "Ophiozona antillarum" and yet only one of 

 the three lots is listed in the Blake report under that species. Mr. Ljnxian 

 apparently was at first inclined to think them young Ophiozonas but was not 

 satisfied with such a disposition of them. It is worth noting that they are from 

 much shallower water than any antillarum in the M. C. Z. collection. In view 

 of the peculiar mouth-parts and the arrangement of the tentacles and their 

 scales, I do not think these little brittle-stai-s can be referred to either Ophiozona 

 or Ophioceramis. 



