ASTEKOIDEA or U.M.S. ' CUALLEKGEll ' EXl'EDlTluX. 21:3 



extremities termiuute iu the ray-ruargiu dimiuish very rapidly in 

 leugtli. 



Colour iu alcobol : Dorsal surface greyisli--\vhite, tiuged with 

 purple on the radial areas, the interradial areas and fringe being 

 purplish grey. Actinal surface livid purple. Ambulacral suckers 

 yellowish grey. 



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

 bottom temperature 0°'3 C. ; GloUgerina-ooze. 



Htmenastee eormosus, n. sp. 



Marginal contour subpentagonal, interbrachial angles very 

 slightly indented, the lesser radius being in the proportion of 73'6 

 per cent. ; i2=19 millim., r=l4 millun. Greneral form depressed, 

 dorsal area rising slightly conoid in the centre. Eadial areas not 

 specially defined, although to a certain extent indicated, the pa- 

 pillse-spinelets being confined to the rays and not encroaching on 

 the median interbrachial portion of the membrane. Marginal 

 fringe very narrow, faintly crenulated, tips of spines roimded and 

 thickened. 



Supradorsal membrane semitranspareut, with closely and 

 regularly reticulated muscular fibrous bands, the bands (which are 

 robust and massively coherent) forming definite meshes over the 

 entire area. The disposition of the tendons is not iu any definable 

 relation to the spinelets. Each mesh is filled up with a fine 

 transparent tissue, in the centre of which is a single large spira- 

 culum, surrounded by a conspicuous white ring. Consequent on 

 the number and regularity of the meshes, the whole area is closely 

 and uniformly covered with spiracula. 



The paxillae are few in number and bear 8 to 5 (or more) robust 

 spinelets, w^hich are well expanded and distributed pretty uni- 

 formly over the area, excepting the median interbrachial space. 

 The rounded tips of the spinelets do not protrude, but simply 

 elevate the dorsal membrane into little rounded tubercles, which 

 rise directly from the surface like warts, and, owing to their 

 somewhat sparse distribution, impart a very characteristic ap- 

 pearance to the dorsal area of the Starfish. Over the median 

 portion of the radii and towards their extremities the tubercles 

 are very much smaller in size and are more closely placed. A 

 conspicuous subpentagonal ring of tubercles surrounds the centre 

 of the disk at the base of the valves of the oscular orifice, the 

 spinelets of fifteen paxillee contributing to its formation. The 



