REPORT ON THE ASTEROIDEA. 487 



Locality. — Station 286. In the Mid-South Pacific, near the meridian of 135° W., 

 approximately midway between Sydney and Valparaiso. October 16, 1875. Lat. 33° 

 29' 0" S., long. 133° 22' 0" W. Depth 2335 fathoms. Red clay. Bottom temperature 

 34° - 8 Fahr. ; surface temperature 63° - Fahr. 



2. Marsipaster hirsutus, Sladen (PI. LXXVIII. tigs. 3 and 4 ; PI. LXXIX. 



figs. 4-6). 



Marsipaster hirsutus, Sladen, 1882, Joum. Linn. Sot. Lond. (Zool.), vol. xvi. p. 205. 



Marginal contour substellate, interbrachial arcs well indented, the minor radius being in 

 the proportion of 60"2 per cent. R=13'5 mm. ; r = 8 - 5 mm. Rays broad at the base, 

 bounded by lines running direct from the median interradial line, with little if any 

 curve or rounding. Abactinal area moderately convex ; rays slightly upturned at the 

 extremities. 



The supradorsal membrane is a fine, irregular, and somewhat spongiose tissue con- 

 tinuous over the whole area, through which the extremities of the spinelets of the paxillse 

 protrude freely. No definite membrane, and no muscular fibrous bands are present. The 

 paxillae have long robust pedicles and bear ten to fifteen fine, long, acicular spinelets ; the 

 investing membrane of the crown is merged into the general supradorsal tissue, and the 

 naked tips of the spinelets, which pass through the tissue, give the surface a some- 

 what hirsute or prickly appearance. The spiracula are comparatively large, very few 

 in number, and very widely spaced. The oscular aperture is inconspicuous ; the valves 

 are formed of spines similar to those on the paxillse generally, and present no special 

 external characters. 



The adambulacral furrows are broad and straight, not petaloid. The tube-feet are 

 arranged in simple pairs. The armature of the adambulacral plates consists of five spine- 

 lets, which form a transverse comb. The two innermost spines are much smaller than 

 the rest, and stand parallel to the furrow, rather in advance of, or aboral to, the other 

 three, which are disposed across the broad adambulacral plate, are articulated on more 

 or less definite tubercles, and form a series at a right ancde to the furrow. The middle 

 spine is longest. The whole series is webbed together with membrane which is deeply 

 indented between the radiating spinelets, but not nearly so much as in Marsipaster 

 spinosissimus. 



The mouth-plates arc broad, having wide lateral expansions, and with an elevated 

 ridge along their line of junction, developing a prominent peak aborally and a rounded 

 point inward. The armature consists of three long, robust mouth-spines, placed on the 

 horizontal margin of each plate, the innermost spine being largest and longer than the 

 spinelets of the adambulacral armature, the outermost less than half its size, and sometimes 

 accompanied by an additional diminutive spinelet. The inner spines stand well away 



