302 Annals of the South African Museum. 



elevated and sharply defined, with paxillae in about half a dozen 

 series; each paxilla has 3 or 4 rather stout spinelets, about 2 mm. 

 long, which radiate widely and push the membrane up above them- 

 selves to such a degree that the paxilla areas look very spiny. 

 Spiracles in small groups of 3-5, lying in widely scattered little 

 jmlches of slightly thickened membrane; there are also a few straight, 

 narrow patches of spiracles extending out onto the interradial mem- 

 brane, much as in H. nobilis. Interradial membrane, smooth and thick, 

 but numerous fine, interlacing fibres can be made out on its surface. 



Actinally the interradial areas are smooth, but fibrous as above; 

 the free area, not touched by actinolateral spines, is 20-25 mm. wide 

 and 10 mm. deep. Adambulacral plates each with two subequal, 

 sharp, slender, slightly diverging, sacculate spines; the saccules ex- 

 tend far beyond the spine-tips. Aperture papillae sacculate, and not 

 peculiar, fully occupying the areas between the bases of the actino- 

 lateral spines. The latter are remarkably short, only a little over 6 mm. 

 long, at the best; there are 25-30 on each side of each ray, but 

 only 4 or 5 are in contact with those of the adjoining ray ; from the 

 fifth to the thirteenth or fourteenth, they are subequal, but they 

 then become rapidly shorter and shorter. Pedicels in two series. 



Oral plates short and wide, projecting greatly at the distal end ; 

 each plate carries on the free lateral margin, which is somewhat 

 flaring, 2 subequal, sharp, slender spines; a much longer and stouter 

 spine stands at the middle of the anterior margin and back of it, 

 near the middle of the plate is a second, similar spine. 



Colour, in alcohol; dorsally, dull pink, abruptly darker even dull 

 claret on the interradial membrane; whole actinal surface, except 

 the dull brown feet, deep, dull red, nearly claret. 



P.F. 16932. Cape Point N.'E. by E. \ E., 40 miles. 800-900 fms. 

 Gr. m. 1 specimen; adult. 



Holotype, South African Museum no. A 6446. 



This handsome Hijmenaster belongs in the same group with glancus 

 and giganteus, but it differs from them both in the very short actino- 

 lateral spines, and the armature of the mouth plates. While it is 

 not impossible that it is the young of giganteus, it seems to me highly 

 improbable. The arrangement of the spiracles is peculiar, reminding 

 one a little of nobilis or perhaps better of koehleri. 



HYMENASTER GENNAEUS *, sp. nov. 



Plate X. 

 R = 75 mm.; r = 60 mm.; R =l'25r. Form almost perfectly 



of noble brith, in reference to the close relationship to H. nobilis. 



