ASTEROIDEA OF H.M.S. ' CHALLENGEB ' EXPEDITION. 233 



and with regularity up to the extremity, the few last maintaining, 

 however, a nearly uniform length, which gives a rounded appear- 

 ance to the fringe at the ray-tips. The actino -lateral spines are 

 finely pointed at their extremities ; and the web-membrane is 

 moderately indented between them. The marginal fringe is per- 

 fectly even, and regular, forming a conspicuous marginal border 

 when seen from the upper suface, although the reticulated dorsal 

 membrane is continued close up to the margin. 



Colour, in alcohol, greyish white. 



Station 300. Lat. 33° 42' S., long. 78° 18' W. Depth 1375 

 fms. ; bottom temperature 1°'5 C. ; Glohigerina-oozQ. 



HtMENASTER GRANIFEHirS, U. Sp. 



Marginal contour almost pentagonal, the interradial angles 

 being very slightly incurved. The radii are more or less attenu- 

 ated or produced at the extremity, which is upturned ; and their 

 effect on the contour is consequently inconspicuous. Minor radial 

 proportion about 69-73 per cent.; i2 = 30 millim., r=22 millim. 

 Eadial areas not specially defined externally from the rest of the 

 dorsal surface. Lateral fringe or web thickened at the margin 

 and little conspicuous, 



Supradorsal membrane delicate. Paxillse-spinelets delicate, 

 with fine sharp extremities protruding well through the dorsal 

 membrane, evenly distributed over the area, but presenting no 

 definite pattern of arrangement. The fibrous bands are rather 

 thin but clearly defined, comparatively few in number, well 

 isolated, and radiate not only to those spinelets which form the 

 immediate circle, but some also pass through the interspaces and 

 reach to the spinelets beyond. In this manner a more or less 

 irregular and very open network is produced, in which, however, 

 a tendency to an interpenetrant hexagonal pattern is discernible 

 as the general plan, here and there — the whole being overlain by 

 a very delicate semitransparent membrane, in wliich a number of 

 small, round, closely-placed granule-like bodies occm\ The spira- 

 cula are small and sporadically placed, very frequently two or 

 even three together in a mesh ; but the groups are well isolated, 

 and the apertures by no means numerous. Oscular orifice large, 

 with 5 regular valves fitting evenly together, each with about a 

 dozen spines, the two innermost being longest, and the others 

 diminishing regularly and gradually, the articulatory base being 

 prominent. 



16* 



