REPORT ON THE ASTEROIDEA. 511 



are covered with a thick fleshy tissue, which is slightly turned over the tips of those 

 spinelets that fall beyond the summit of the interbrachial arc, and extends up to within a 

 short distance of the extremity of the ray, gradually diminishing in breadth as it pro- 

 ceeds outwards. The margin of this supplementary fringe is thickened, and furnished 

 with a powerful muscular band. 



Colour in alcohol, a rather livid pink, the ambulacral furrows and tube-feet being a 

 yellowish white. 



Locality. — Station 158. South of Australia, 1009 miles south-west of Cape Otway. 

 March 7, 1874. Lat. 50° 1' 0" S., long. 123' 4' 0" E. Depth 1800 fathoms. Globi- 

 gerina ooze. Bottom temperature 33 0- 5 Fahr. ; surface temperature 45°'0 Fahr. 



Remarks. — This exceedingly handsome species is characterised by the definitely raised 

 areas of the paxillse-crowns. A similar structure occurs in Hymenaster sacculatus, but is 

 not so strikingly developed. The two species may be readily distinguished by the structure 

 of the supradorsal membrane, by the disposition of the spiracula, by the armature of the 

 adambulacral plates, and by the general form. The colour also is different. 



12. Hymenaster crucifer, Sladen (PI. LXXXIX. figs. 1 and 2 ; PI. XCI. figs. 1-3). 



Hymenaster crucifer, Sladen, 1882, Journ. Linn. Soc. Lond. (Zool.), vol. xvL p. 227. 



Marginal contour subpentagonal. Interbrachial arcs very slightly indented, the minor 

 radius being in the proportion of 66'6 per cent. R= 51 mm. ; r = 34 mm. Rays tapering 

 to a fine extremity, which is somewhat attenuated and produced. Marginal fringe com- 

 paratively insignificant as seen from above, and narrowing rapidly towards the extremity 

 of the rays. Form depressed, more convex on the actinal than on the abactiual surface. 



The supradorsal membrane is rather thin; the muscular fibres are numerous, thick, and 

 radiate regularly from the tips of the spinelets. The paxillsj are numerous, though 

 somewhat widely spaced, and bear 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 round the tip are merged together 

 and form a homogeneous " cap ; " the caps of each of the spinelets of a crown coalesce, and 

 thus produce the subcruciform or rhomboid elevation above mentioned. The paxillse 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 lines, four to eight 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 

 abactinal surface. The oscular orifice is large, the valves all webbed together, and the 

 spinelets quite hidden in membrane, the whole of which is uuiformly punctured with a 



