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BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



nor the gonads of Sidenaster are described — one of the unfortunate 

 results of drying unique specimens. I do not know whether Siden- 

 aster has the incomplete unpaired interradial series of actinal in- 

 termediate plates. The fascioles between the adambulacral plates, 

 which I examined in the type-specimen, form one of the most 

 striking features of the genus. They are densely lined with small 

 delicate spinelets, and are therefore similar to marginal fascioles. 

 Such is not the case in Anthosticte, Tethyaster^ or Molraster. 



The distribution of gonads and deposits of tube feet are unknown 

 in Moiraster. Koehler describes the marginal fascioles as '" pen 

 profonds," while Sladen says they are deep, but the discrepancy 

 is only apparent, for Sladen knew no genera with very deep 

 fascioles, such as Dipsacaster. Anthosticte differs from Moiraster 

 in respect to the marginal fascioles and the thin elevated inter- 

 vening ridges of the marginal plates. The inferomarginal and 

 actinal spinelets of Anthosticte are slender, and not flat, spatulate, 

 and chisel-shaped. Xo pedicellariae 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 paxillae of Moiraster 

 are probably lower than those of Anthosticte^ 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 Anthosticte 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 Sideriasterf 



Conipurisoii of the cliaracters of Anthosticte, Tethyaster, Sidenaster, and 



Moiraster. 



1 According to Koehler, Trans. Roy. Soc. Edinburgh, vol. 46, 1908, pt. 3, p. 631, pi. li 

 flg. 110, this series seems to be present in an incipient form. 



