MUSEUM OF COMPARATIVE ZOOLOGY. 223 



Ophiochondrus convolutus Lym. 

 Ophiochondrus convolutus, Bull. Mus. Comp. Zoiil. Vol. I. No. 10, p. 328. 1869. Ill, 

 Catal. Mus. Comp. Zobl. VI. PI. II. Fig. 7. 



Station 16, 292 fathoms, 2 specimens. Sigsbee, off Havana, 175 fathoms, 



1 specimen. 



Ophiozona tessellata sp. nov. 



Plate III. Figs. 43-45. 



Special Marks. — Three spaced arm-.spines, about two thirds as long as an 

 arm-joint. Two large tentacle-scales, side by side. A small thick spine or 

 spike outside each radial shield. 



Description of an Individual (Station 1 1). — Diameter of disk 8 mm. Length 

 of arm about 35 mm. Width of arm without spines 1.5 mm. Eleven short, 

 close-set, rounded papillae to each mouth-angle, those within being smaller and 

 more pointed. Mouth-shields longer than broad, and wider within than with- 

 out, small, hexagonal, with a blunt angle inward, outer side rounded, and 

 slightly re-entering curves on the lateral sides ; length to breadth 1.2 : 1. 

 Side mouth-shields small, much curved, slightly swollen, longer than wide, 

 with rounded ends inward, where they just meet. Under arm-plates four- 

 sided, much wider without than within ; having the outer side curved and 

 lateral sides re-enteringly curved. Side arm-plates small and lowest at their 

 outer edge, meeting neither below nor above, where they are separated by 

 smooth, slightly swollen, quadrangular upper arm-plates, having a curved outer 

 edge wider than the inner one. Disk thin and round, covered with small, 

 somewhat swollen plates, whereof six primaries in a central rosette are con- 

 spicuous by their larger size ; in each interbrachial space there is a radiating 

 row of three differently shaped jdates. Radial shields of a rude egg-shape, with 

 the small end inward ; separated their whole length by a single row of plates, 

 whereof the innermost is nearly as large as a primary. On the outer edge of 

 each radi;il shiehl are two narrow plates, on which stands a short, blunt, rounded 

 spine. Genital opening extending nearly to margin of disk ; the rest of the 

 lower interbrachial space outside the mouth-shield is occupied by small irregu- 

 larly shaped plates. Three short tapering arm-spines, evenly spaced on the 

 outer edge of the side arm-plate, and about two thirds as long as an arm-joint. 

 Two flat rounded tentacle-scales on the inner edge of each tentacle-pore. 

 Color in alcohol, pale straw. 



Station 11, 242 fathoms, 1 specimen. 



This species stands near 0. insularia (Bull. Mus. Comp. Zool. V. No. 7, 

 p. 127), but is readily distinguished by its two large tentacle-scales and differ- 

 ent under arm-plates, and by the little sjiine outside the radial shield. 



Ophiozona nivea Lym. 

 Ophiozona nivca, 111. Catal. Mus. Comi). ZoiJl. No. VIII. Pt. II. p. 9, Figs. 85, 86. 1875. 

 Station 16, 292 fathoms, 1 specimen. Station 21, 287 fathoms, 3 specimens. 

 Sigsbee, off Havana, 177 fathouLS, 1 specimen. Sigsbee, off Havana, 242 

 fathoms, 2 specimens. 



