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PROCEEDINGS OF THE NATIONAL MUSEUM. 



vol. 40. 



sticte are slender, and not flat, spatulate, and chisel-shaped. No 

 pedicellarise are described for Moiraster. If the gonads are found to 

 extend to the end of the ray, it may become necessary to unite the 

 two genera, although the difference in the marginal fascioles will 

 remain. The paxillas of Moiraster are probably lower than those 

 of AntJiosticte, and less delicate. The character of the gonads is 

 important, and is apparently very reliable for generic groups, but not 

 for higher ones. 



It seems better to keep AntJiosticte separate rather than to unite 

 it with another genus, especially as it is not at all evident into which 

 of the three groups it would go with the least disturbance. 



The following table recapitulates the characters mentioned above. 

 Will some one enlighten us concerning the gonads and tube feet of 

 Moiraster and Sideriaster? 



Comparison of the characters of Anthosticte, Tethyaster, Sideriaster, and Moiraster. 



Family GONIASTERIML 

 PONTIOCERAMUS, new genus. 



Stellate, with a large disk and relatively short rays. Related to 

 Plinthaster Verrill, but differing in having the surface of the abactinal 

 plates perfectly smooth, not covered with minute bosses, in having 

 the plates of the papular areas low-tabulate, and the adambulacral 

 plates with an angular furrow margin armed with numerous short 

 stubby spinelets; no enlarged subambulacral spine on distal part of 

 ray. Abactinal and marginal plates bordered by a single series of 

 small granules, the latter also with some on lateral face of ray, all 

 flush with level of plate. Last few superomarginals in contact medi- 

 ally. Actinal intermediate plates reaching far along ray, closely 

 granulate, and with small bivalved excavate pedicellarise about as 

 high as wide. Adambulacral plates proximally very narrow, distally 

 becoming wider; with a large subambulacral toothed bivalved pecli- 

 cellaria, and 10 or 11 furrow spinelets in angular series. No smaller 

 secondary abactinal plates. 



Type. — Pontioceramus grandis, new species. 



