A. E. Yerrill — Eevision Genera and Species of Starfishes. 175 



The abactinal plates are rounded, with a marginal row of coarse 

 round granules ; the center is occupied, in most cases, by a broad, 

 low, bivalve pedicellaria, nearly as wide as the plate. Each plate 

 of the radial areas and of the center of the disk has five or six papu- 

 lar pores around it. The apical plate is irregularly ovate, with a 

 pair of small apical spines. 



The actinal plates are not numerous, much crowded, and closely 

 united, so that their outlines are obscure. They have marginal 

 granules and a large central pedicellaria, like those of the actinal 

 plates, but rather larger. 



The adambulacral plates are narrower ; each has two, or some- 

 times three, flattened, blunt or spatulate, often crooked furrow 

 spines ; a larger clavate spine in the next row. Standing on the cen- 

 ter of the plate; and three to five much smaller, unequal, conical or 

 clavate spinules in a group on the actinal end. 



The oral spinules are numerous, crowded, and much compressed. 



Greater radius, 17.5"^"'; lesser, 8.5 to 9.5"^°^. 



Taken by the Albatross at station 2668, N. lat. 30° 58' 30", W. 

 long. 79° 38' 30", in 268 fathoms, gray sand (No. 18,425, one young). 



The discovery of this tropical species is of special interest, for the 

 genus was previously .represented by only two species ; one [H. 

 phrygiana^ found in the boreal parts of the North Atlantic, on both 

 coasts, extending on the American coast to Cape Cod in moderately 

 deep water ; the other {^H. magellanica) from the region of Pata- 

 gonia. The occurrence of the genus in the intermediata tropical 

 region is, therefore, significant. 



Cladaster Ver., gen. nov. 



Stellate, with a broad, flat disk; interradial margins regularly in- 

 curved; rays tapered. 



Marginal plates of both series rather large, not numerous, en- 

 croaching upon both sides of the disk, regularly paired, except dis- 

 tally, decreasing regularly in size ; about four pairs of the dorsal 

 ones are in contact medially. No odd interradial plates. Apical 

 plate and those adjacent, small. 



The marginal plates and all the actinal and abactinal plates are 

 normally granulated, but in the type many of the marginal and 

 abactinal plates have irregular, partially naked central patches, 

 covered with small pits where granules have fallen off. 



Abactinal plates all polygonal with rounded angles, rather large, 

 not numerous; the median row of the rays is distinct, and bordered 



