198 



MK. W. PEECT SLADEN ON THE 



dary or superficial moutli-spines (one on each plate) not longer 

 than the mouth-spines, scarcely if at all stouter, subcylindrical 

 and not pointed, covered rather thickly with membrane. 



Actino-lateral spines completely hidden in a very thick fleshy 

 membrane, vt'hich extends as a saccular prolongation beyond their 

 extremities, forming an aborted lateral fringe that projects slightly 

 beyond the margin of the disk and rays. 



Colour, in alcohol, varying from light warm brown to purplish 

 grey. 



Station 313. Lat. 52^ 20' S., long. 68° 0' W. Depth 55 fms. ; 

 bottom temperature 8°'8 C. ; sand. 



Ebtasteb peeegbinatoe, n. sp. 



Marginal contour not greatly indented, the lesser radius being 

 in the proportion of 65'85 per cent. ; E = 4:l millim., r=27 millim. 

 Interradial angles subangular or faintly rounded. Eadii short, 

 thick, blunt and rounded at the extremities, which are slightly 

 upturned. Dorsal profile bombous and rather high. Actinal 

 area flat or subconvex. 



Supradorsal membrane thick and regularly reticulated. Pax- 

 ilJse with a crown of 5 to 10 spinelets, one directed to the centre 

 of the mesh, the rest expanded very slightly ; six radiating fibrous 

 bands pass from the central spinelet to the mesh-fibres ; and tlie 

 interspaces include 2 or 3 large spiracula. All the spinelets 

 are uniformly protuberant, and that only to a slight degree .; 

 they are rather closely placed ; and the whole dorsal area is thickly 

 covered with rather fleshy wrinkly skin, presenting a somewhat 

 spongy and subpapillose appearance, and a slightly scabrous feel- 

 ing to the touch. The primary meshes are not very distinctly 

 marked out superficially ; and the hexagons consequently appear 

 to overlap or run into one another in many cases. Oscular ori- 

 fice small and inconspicuous. 



Ambulacral furrows broad and more or less petaloid, the closely 

 placed and prominent transverse spine-combs adding greatly to 

 the appearance of breadth. Sucker-feet arranged in quadruple 

 series. The combs of ambulacral spines are broad, a feature 

 further enhanced by their method of arrangement. Each alter- 

 nate comb has usually two spines less : in this way combs of 7 

 to 8 spinelets alternate regularly with combs of 5. The larger 

 combs radiate well over the furrow, whilst the smaller ones, on 

 the other hand, are considerably retired from the margin ; the 



