220 ME. W. PEECT SLADEIS' OK THE 



well beyond the membrane, and give the appearance of a sharply 

 indented margin. The web of tbe actino-lateral spines, which 

 also forms the ventral floor, is made up of very thickly packed, 

 fine, delicate crossing fibres. 



Colour, in alcohol, liglit brown above, pure white beneath. 



Station 286. Lat. 33° 29' S., long. 133° 22' W. Depth 2835 

 fms. ; bottom temperature 0^"8 C. ; red clay. 



HXMENASTEB CAENOSITS, n. Sp. 



Marginal contour substellate ; interradial angles well defined, 

 the lesser radius in the proportion of 58'2 per cent. ; i2 = 103 

 millim., r= 60 millim. Eadii tapering regularly to the extremity. 

 Dorsal area slightly convex, rising somewhat conoid in the 

 centre, radii rather roundly arched. Actinal area flat or convex. 

 A narrow, thick, fleshy conspicuous fringe surrounds the entire 

 margin. 



Supradorsal membrane thick, fleshy, opaque. Paxillse-spine- 

 lets uniformly and closely distributed over the whole area, 

 greatly protruding and covered with membrane, which gives 

 them the appearance of broad-based, robust, conical thornlets, 

 about 3 to 4 millim. in height, springing from the general sur- 

 face. They are very uniform in size ; and no definite order of 

 arrangement is perceptible, nor is it possible to distinguish the 

 individual crowns to which the spinelets belong. A more or less 

 homogeneous muscular layer overspreads the whole area ; and no 

 specialized bands or fibres are superficially apparent. The spiracula 

 are quite microscopic, and confined to small round groups, con- 

 taining ten or more very closely crowded together, placed in the 

 hollow interspaces between the spinelets, and the whole quite 

 invisible to the naked eye. Oscular orifice large, with valves 

 broad and squarely truncate at the extremity, all webbed together ; 

 the prominent thorn-like spinelets above mentioned marking out 

 a circle at their bases of attachment 24 millim. in diameter. 



Ambulacral furrows wide (8"5 millim.), nearly uniform in 

 breadth until near the extremity, where they gradually converge. 

 Sucker-feet numerous and closely crowded, but maintaining the 

 regular biserial arrangement. Ambulacral spinelets 2, long and 

 needle-shaped, placed side by side in line w^ith the margin of 

 the furrow, or the very slightest trace oblique. The adoral 

 spinelet is somewhat the longest ; and both are invested with an 

 extensive saccular membrane, extending beyond the extremity, 



