ASTEEOIDEA OF H.M.S. ' CnALLENGEE, ' EXPEDITION. 227 



tliis supplementary fringe is thickened, and furnished with a 

 powerful muscular band. 



Colour, in alcohol, a rather livid pink ; ambulacral furrows and 

 Bucker-feet a yellowish white. 



Station 158. Lat. 50° 1' S., long. 123° 4' E. Depth 1800 fms. ; 

 bottom temperature 0°'3 C. ; Glohigerina-oozQ. 



Htmenastee ceucieee, n. sp. 



Marginal contour subpentagonal ; interradial angles very slightly 

 indented, the lesser radius being in the proportion of 66'6 per cent.; 

 i2 = 51 millim., r = 31jmillim. Radii tapering to a fine extremity, 

 which is somewhat attenuated and produced. Marginal fringe 

 comparatively insignificant as seen from above, and narrowing 

 rapidly towards the extremity of the rays. Form depressed, more 

 convex on the actinal than on the abactinal surface. 



Supradorsal membrane rather thin, muscular fibres numerous, 

 thick, and radiating regularly from the tips of the spinelets. 

 Paxillae numerous, though somewhat widely spaced, bearing a 

 crown of four or sometimes five spinelets, which usually elevate 

 the membrane into slightly raised, Maltese-cross-shaped areas. 

 The spinelets are sharply prominent ; and the fibres for a short 

 distance around the tip are merged together and form a homo- 

 geneous "cap;" the caps of each of the spinelets of a crown 

 coalesce, and thus produce the subcruciform or rhomboid eleva- 

 tions above mentioned. The paxiUse are well spaced, and are 

 arranged in longitudinal lines along the rays. No spiracula occur 

 on the raised areas ; but in the intermediate spaces they are very 

 numerous and closely placed, the intervals between the thick 

 radiating bands being very narrow, and occupied by a great 

 number of small spiracula placed close together in line, 4 to 8, 

 or even more in each, and separated from one another by only 

 the finest dissepiment. The numerous spiracula and the isolated 

 unpunctured cruciform areas give a striking character to the 

 dorsal surface. The oscular orifice is large, the valves all webbed 

 together, and the spinelets quite hidden in membrane, the whole 

 of which is uniformly punctured with a great number of small 

 spiracula, not quite so closely placed as those on the disk, and 

 not arranged in lines. 



Ambulacral furrows rather widely petaloid, rapidly constricted 

 at the extremity. Ambulacral spines three, short, nearly uniform 

 in length, pointed, and covered with a membrane expanded into 



