A. E. Verrill — Revision Genera and Species of Starfishes. 209 



This species was taken by the U. S. Fish Commission Steamer 

 Albatross, at many stations, from off Martha's Vineyard to the 

 Carolina coasts, in 56 to 400 fathoms or more. It was often asso- 

 ciated with 0. hispidus. 



In form and general appearance it resembles O. hisjndtis, but is 

 easily distinguished by the higher marginal plates, and especially by 

 the slender setiform spinules of all the plates on the under side. 



Odontaster robustus Ver., sp. nov. 



Plate XXIX. Figures 4, 4a. 



Form broadly stellate, with short, rapidly tapered rays and thick 

 margins. The sides are regularly incurved. Radii about 1 : 1^. 



The marginal plates are larger and thicker than in the two preced- 

 ing species. Those of the two series correspond closely in size and 

 position. There are 27 of each series on each side of the body, in 

 the type. They encroach considerably upon the disk, both above 

 and below, and rise distinctly above the abactinal plates, thus form- 

 ing a conspicuous margin. They are transversely oblong, about 

 twice as high as broad. About four pairs of the distal dorsal plates 

 are in contact medially. 



The odd interradial plates are small and wedge-shaped, and do 

 not reach the marginal sutural groove, but in this groove, opposite 

 the odd interradials, there may be a small, odd, ovate plate. This is 

 lacking, or xqvj small, on two of the margins of the type. The 

 sutural grooves are narrow and deep, with marginal fascioles of 

 small slender spinules. Both series of marginal plates are thickly 

 covered with small, slender, setiform spinules, those of the lower 

 series somewhat larger and longer than those of the upper ones. 



The abactinal plates are small, round, well separated, paxilliform. 

 Those of the radial areas have a rather high column, somewhat capi- 

 tate, with the top somewhat convex and covered with a divergent 

 cluster of small, slender, acute, setiform spinules. 



The papular pores are conspicuous and occupy five large radial 

 and a disconnected central area ; those in the central parts of each 

 area are much larger than those at the edges ; about six surround 

 each plate. 



The actinal plates are squarish and form about four rows parallel 

 with the ambulacra; they are separated by rather wide grooves, and 

 each bears a thick group of elongated, slender, setiform spinules. 



Trans. Conn. Acad., Vol. X. August, 1899. 



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