220 A. E. Verrill — Revision Genera and Species of Starfishes. 



Sideriaster grandis Ver., sp. nov. 



Plate XXX. Figures 8, 80, Sh. 



Large, regularly five-rayed, with a broad, somewhat inflated disk, 

 regularly and broadly incurved at the sides. The rays are rather 

 long and rapidly tapered. Radii as 1: 8.4. Greater radii, 133-]38™'"; 

 lesser, 40""\ 



The margin is formed mostly by the upper plates, which do not 

 extend at all upon the upper side. They are small and short, those 

 on the interradial margins shortest and highest, at least four times as 

 high as long. They are covered with coarse rounded granules, and 

 bordered with fascioles of slender spinules. The lower marginals 

 are of the same length and extend on the under side considerably. 

 They are covered closely with small appressed, flattened spinules, 

 largest centrally, grading laterally to the marginal fasciolated spin- 

 ules. On the middle of each plate there is a vertical row of about 

 four stout, tapered, more or less flattened, acute spines. 



The abactinal paxillse are round and high, remarkably uniform in 

 size, arranged on the rays in imperfect, transverse, oblique rows. 

 They bear a round, rosette-like cluster of rather coarse, short, clavate 

 or capitate, divergent spinules, of which one is usually central, with 

 6 or V in a circle around it, while about 15 to 18 form the marginal 

 row, interlocking with those of the adjacent plates, so as to conceal 

 the papular pores. The latter are rather large and regularly 

 arranged over the whole disk and nearly to the ends of the raj^s, 

 usually six around each paxilla. The bases of the paxill^ appear 

 stellate. 



The madrej^oric plate is remarkably large and flat or slightly con- 

 cave, with very numerous and thin radiating gyri. 



The actinal plates are granulated nearly like the upper marginal 

 plates. Other under parts have been described above under the 

 generic description. 



Pedicellariae occur in small numbers on the adambulacral plates 

 and on the first row of actinals. They have two or three short, 

 stout, flattened, spinuliform blades, similar in size to the adjacent 

 spinules. 



One specimen (No. 10,877) was taken by the Albatross at station 

 2378, in Gulf of Mexico, in 68 fathoms. 



