REPORT ON TUP: ASTEROIDEA. 457 



The ambulacral furrows are contracted ; and the tube-feet, which have a crowded 

 appearance, have a well-developed fleshy terminal disk. 



Colour in alcohol, a bleached greyish white. 



Locality. — Station 150. Between Kerguelen Island and Heard Island. February 

 % 1874. Lat. 52° 4' 0" S., long. 71° 22' 0" E. Depth 150 fathoms. Coarse gravel. 

 Bottom temperature 35°'2 Fahr. ; surface temperature 37° - 5 Fahr. 



Remarks. — This species is nearly allied to Solaster endcca, of which it is perhaps the 

 southern representative. Solaster subarcuatus is readily distinguished from the North 

 Atlantic species by the form of the rays, by the larger and more widely spaced paxillse, 

 which are also more regularly arranged, and by the armature of the adambulacral plates. 



5. Solaster torulatus, n. sp. (PI. LXX. figs. 3 and 4 ; PL LXXII. figs. 3 and 4). 



Rays eight. R = 48 mm. ; r = 17 mm. R< 3 r. Breadth of a ray at the base, 12 mm. 



The rays are moderately elongate, broad at the base, slightly tumid on the inner half 

 and then rapidly tapering to the extremity, the outer part being narrow and cylindrical. 

 At the base of the rays on the disk there is a sharply defined sloping ravine or sulcus, 

 continued from the summit of the interbrachial arc for a considerable distance on the 

 disk, causing the disk to appear at first sight much smaller than it really is, and the rays 

 to be crowded and pressed together at their bases. The abactinal surface of the disk is 

 sliohtly convex. The actinal surface is plane. The interbrachial arcs are acute. 



The abactinal surface is beset with very short, small, paxilliform groups of spinelets. 

 The spinelets, of which there are eight to ten in each crown, are so small and compactly 

 crowded that they are only distinguishable with a magnifying-glass ; the groups or 

 paxillse appearing to the naked eye only like small, regular, uniform, semiglobular tubercles. 

 These are well spaced apart and the interspace is occupied by a single papula. The 

 paxillse are arranged with great regularity, which may be resolved on careful examination 

 into longitudinal and obliquely transverse lines. 



The marginal plates (the representatives of the infero-marginal series) are quite on 

 the actinal surface, to which they form the border, and are invisible when the starfish is 

 viewed from above. They resemble large compressed paxillse, the pedicle being large and 

 massive, with the major axis at right angles to the median line of the ray, and surmounted 

 by a crown of fifteen to twenty short compactly grouped spinelets. There are about 

 thirty-five or thirty-six between the median interradial line and the extremity, those on 

 the inner half of the ray being large and widely spaced, but they diminish in size as they 

 proceed outward and become almost microscopic towards the extremity. 



The paxillse w T hich represent the supero-marginal plates are small in comparison with 

 the infero-marginal plates, and very little larger than the neighbouring paxillse of the 

 abactinal area. They alternate with the infero-marginal plates and consequently stand 

 opposite the interspace between each of the large marginal paxillse. 



(ZOOL. CHALL. EXP. — PART LI. 1888.) 58 



