234 BULLETIN OF THE 



specimens. Station 158, 148 fathoms, 1 specimen. Station 164, Guadeloupe, 

 150 fathoms, 11 specimens. Station 220, lliO fathoms, 1 specimen. Station 

 224, 114 fathoms, 1 specimen. 



0. marmorea is nearest 0. nivea, from which it differs in. its swollen disk- 

 plates, side arm-plate and side mouth-shields, its smaller upper arm-plates, and 

 shorter arms, and in granulation on the lower interbrachial space. 



Ophiozona clypeata sp. nov. 



Plate III. Figs. 13-15. 



Special Marks. — Eleven close-set, lumpy mouth-papilla; to each angle. 

 Side mouth-shields large and wide. Three moderately stout arm-spines, about 

 as long as a joint. 



Description of an Individual (Station 219). — Diameter of disk 10 mm. 

 Length of arm 65 mm. Width of arm near disk 2 mm. Eleven short, 

 lumpy, crowded moutli-papillaB to each angle, whereof the one next the outer- 

 most is widest. Mouth-shields blunt spear-head shape, with the point inward ; 

 length to breadth, 1.5 : 1. Side mouth-shields rather wide and fully meeting 

 within. Under arm-plates thick, but not ridged, much wider without than 

 within where they are bounded by a wide truncated angle, Avhile the outer is a 

 broken curve and the lateral sides are re-entering curves. Side arm-plates short 

 and stout, with a low spine-ridge. Upper arm-plates twice as broad as long, 

 and much wider without than within. Disk round and flat, covered with dis- 

 tinct rounded slightly swollen overlapping scales, among which the prima- 

 ries are conspicuous by their greater size. Radial shields short, oval ; length 

 to breadth, 1.2 : 8. In the interbrachial spaces below, the scales are of uniform 

 size, about three in the length of 1 mm. Genital openings long, extending from 

 outer corners of the mouth-shield quite to margin of disk. Three moderately 

 stout, cylindrical, tapering, blunt arm-spines ; the two upper ones as long as a 

 joint, the lowest a little longer. Two rudely semicircular tentacle-scales on 

 the side arm-plate, whereof the one next the under arm-i)late is smaller. Color 

 in alcohol, nearly wliite. 



Station 219, off Saint Lucia, 151 fathoms, 1 specimen. Station 232, St. 

 Vincent, 88 fathoms. 



By its smaller disk-scales and longer and more pliable arms this species 

 connects the large-scaled and stiff-armed Ophiozona; with the type 0. impressa. 

 It shows, too, the affinity of the genus to Ophiochiton through 0. lentus. 



Ophiozona nivea Ltm. 



Station 129, Santa Cruz, 314 fathoms. Station 145, St. Kitts, 270 fathoms. 

 Station 146, St. Kitts, 245 fathoms. Station 147. St. Kitts, 250 fathoms. Sta- 

 tion 148, St. Kitts, 208 fathoms. Station 154, Montserrat, 298 fathoms. 

 Station 155, Montserrat, 88 fathoms. Station 172, Guadeloupe, 62-180 fatb- 



