304 VERRILL 



The open suture between the dentary plates of the jaws; the 

 movable hyaline spine, attached only by its base, at the apex of the 

 jaw, together with the very spinose character of the abactinal 

 paxillae and marginal plates, separate this genus from its allies. The 

 marginal plates are also larger than in most of the other groups, 

 and the adambulacral plates bear usually three or four spines in 

 the furrow-series. 



ODONTASTER CRASSUS Fisher. 



Odontaster crassus FISHER, op. cit., 1905, p. 302; op. cit., 191 ib, p. 154, pi. 

 xxix, figs. 1-4; pi. LVI, fig. 6. 



Form stellate with short rays; radii of the type, 13 mm. and 

 21 mm.; ratios, about 1:1.5. Marginal plates few, massive, eight 

 in a row in the type, covered with granule-like spinules. Odd 

 epioral hyaline spine is lanceolate, recurved. Interactinal plates 

 squarish, bearing five to twelve radiating, short, stout, pointed 

 spinules. 



Dr. Fisher records it from ten stations, in 43 to 284 fathoms, from 

 off Monterey to San Diego, California. 



Family ASTEROPW2E Fisher. 



GymnasteriidcE PERKIER, 1884, pp. 165, 229. Sladen, 1889, p. 355. 

 Gymnasteriidce -\- Poraniidce PERRIES, op. cit., 1894, pp. 163, 227. 1 

 Asteropida FISHER, 1908, p. 90; I9H&, p. 247. 



Disk usually large; rays short and broad. Dorsal ossicles some- 

 times tesselated, in regular radial rows, more often irregular, some- 

 times partly abortive, sometimes reticulated ; either covered with a 

 thick, smooth or granulated skin, or spinose, or spinulose. 



Marginal plates various, sometimes prominent, usually oblique or 

 overlapping, sometimes with a small group of spinules on the outer 

 edge, or with a single spine; sometimes nearly abortive, and the 

 edge of disk thin. 



Interactinal plates sometimes numerous, usually in regular oblique 

 rows. Papulae in dorsal radial areas, sometimes intermarginal. 

 Pedicellariae commonly lacking; when present, valvular, with two to 

 four valves. 



'It seems to the writer very doubtful whether the Poraniidse should be 

 combined with this family. Some of the genera are very similar to Asterinidae 

 in form and structure. 



