ASTEEOIDEA Or H.M.S. ' CHALLENGEE ' EIPEDITIOIT. 223 



Station 235. Lat. 34° 7' N., long. 138° 0' E. Depth 565 fms. ; 

 bottom temperature 3°"3 C. ; mud. 



Htmenaster yicaeius, n. sp. 



Marginal contour subpeutagonal ; interradial angles ■well in- 

 dented, the lesser radius being in the proportion of 69"2 per cent. ; 

 i2=39 millim., r=27 millim. The lateral fringe is more or less 

 distinct; and its margin forms a line that curves outwards after 

 passing the middle of the ray, adding greatly to the appearance 

 of its breadth ; the margin then suddenly contracts and empha- 

 sizes the rapid tapering of the ray at the extremity. 



Supradorsal membrane thin and papyraceous in appearance. 

 Muscular fibres numerous and irregular, rather thick, closely 

 placed, radiating from the tips of each spinelet to those around, 

 and thus forming an interlacing web with moderately large 

 meshes of rhomboid or quadrate form. The interspaces are filled 

 in with transparent membrane, punctured in the centre by a spi- 

 raculum ; these are moderately large, well-spaced, and uniformly 

 though irregularly distributed over the dorsal area. Paxillse 

 numerous, — carry 4, 5, or 6 spinelets, which are rather short, 

 pointed — their tips elevating the membrane into small pointed 

 papillae, which are very evenly spaced over the dorsal area and 

 appear to rise sharply from the surface, whilst their small size 

 and comparative closeness of position give an easily recognizable 

 character to the Starfish. 



Ambulacral areas moderately broad, lanceolate in outline, 

 tapering rather rapidly before they reach the extremity, which is 

 in consequence somewhat produced. Ambulacral spines two, 

 rather short, cylindrical and pointed, covered with an extensive 

 investing membrane, which forms an elongate sacculus at the tip, 

 and also adds greatly to the apparent robustness of the spinelets. 

 Aperture-papillae large, acumino-spatulate, wide and rotund at 

 the base, often contracting rapidly to a point at the free extre- 

 mity, or simply rounded. 



Mouth-plates small, elongate, narrow, keeled, prominent ab- 

 orally, each bearing two short robust secondary surface-spiues, 

 one near the adoral extremity, and the other placed more aborally, 

 near the middle of the plate. The horizontal margins of the 

 plate which fall into the actinostome are expanded into a rather 

 wide flange, upon the edge of which are situated 4 or 5 short 



