286 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



Ancorina (). Schmidt (1862, p. 51). Sollas (1888, p. 182) includes 

 here forms with a well-developed fibrous cortex, with euasters and 

 sanidasters. Lendenfeld, 1903, enlarges the genus to include several 

 others as subgenera. In 1906 (p. 253) Lendenfeld uses the genus 

 in Sollas' sense plus Stryphnus, limiting it to forms with dicho- 

 triaenes. The genus is understood by me in Sollas' sense. The 

 question as to the distinction between sanidasters and roughened 

 microrhabds, and the separation of Ecionemia from Ancorina, is 

 touched upon under Ecionemia. 



Sanidastrella Topsent (1892 c, p. xvui). To be retained! 1 It would 

 seem there is nothing in the speculation to mark off the genus from 

 Ancorina. The megaseleres and sanidasters are essentially the 

 same, and large oxyasters occur in Ancorina — as, for example, in 

 A. wageneri O. Schmidt, merged in the type species, A. cerebrum 

 O. Schmidt, by Lendenfeld, 1891, p. 29, the ray length here reach- 

 ing 45 y. (Sollas, 1888, p. 189; Lendenfeld, 1894, p. 35). 



Rhabdodragma Dendy (1916, p. 239). Distinct from Ecionemia? 



Stryphnus Sollas (1888, p. 171). Lendenfeld, 1903, 1906, makes it a 

 subgenus of Ancorina. 



Algol Sollas (1888, p. 200). Subgenus of Ancorina in Lendenfeld, 

 1903; presumably also in Lendenfeld, 1906. 



Penares Gray (1867, p. 542). Equivalent to Papyrula O. Schmidt, 

 as used by Sollas, 1888, p. 198. Stellettids with small, smooth 

 oxeas usually controtylote, which are densely aggregated in the 

 ectosome. This small oxea, or " microxea " Authors, is a very dif- 

 ferent spicule from the micorhabd of Ecionemia, as is shown not 

 only by its shape but by its much greater and very variable size. 

 The length of the spicule ranges in the type species, P. helleri (O. 

 Schmidt), from 20 to 175 u, its thickness from 2 to 10 \l (Lenden- 

 feld. 1903, p. 61). In P. sollasi Thiele (1900, p. 23), the spicule 

 ranges in length from 26 to 90 pi; in P. foliaformis Wilson (1904, 

 p. 114) from 60 to 160 |a; in P. obtusa Lendenfeld (1903, p. 263) 

 from 100 to 150 v .\ in P. scterobasa Topsent (1904, p. 83), the 

 length is 100 \>.. thickness at the middle 12 [>,. 



Dercitus Gray. Position? See p. 277. 



Galthropella Sollas. See p. 278. 



Chelotropella Lendenfeld. See p. 278. 



Appendix— Papyrrda O. Schmidt (1868, p. 18. Sollas. 1888, p. 199. 

 Lendenfeld, 1903. p. 69) may be provisionally retained for forms 

 differing from P< Hares in the absence of euasters. Lendenfeld. 

 1906, p. 227, regards the small oxeas as derived from metasters 

 and enrolls the genus in the Theneidae. 



