296 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



same complex are certain Japanese forms. The probability is that 

 all the forms with this complex are very closely related. The Japa- 

 nese forms alluded to are JS. orientalis Thiele (1898, p. 14), the sur- 

 face of which is covered with a furze consisting largely of protri- 

 aenes; S. validissima Thiele (1898, p. 13), with protriaenes having 

 clads 200 fi long, with dermal strongylasters, and with choanosomal 

 oxyasters having man}^ rays. 



STELLETTA RADICIFERA, var. ROBUSTA, new variety. 



An imperfect specimen from the same station (D5179) as the 

 above possibly belongs in the same species. Preparations of the two 

 are, however, easily distinguishable, and it would therefore be arbi- 

 trary to combine them, although the differences may be found to fall 

 within the range of individual variation. 



This sponge which I provisionally designate a new variety differs 

 from the type in the following points: 



(1) The dichotriaenes are larger. The rhabdome is 5-6 mm. by 

 70-85 [x; protoclad 100-120 by 60 pi; deuteroclads 210-260 [x long. 



(2) The anatriaenes are larger. The rhabdome is 6-10 mm. by 

 32 [i., clads 70-100 \i long. 



(3) The oxeas seem to reach a greater common average of size. 

 At any rate spicules 5 mm. by 50 \i Avere easily found. 



(4) The dermal oxyasters are somewhat smaller, 6-8 jjl in diameter. 



(5) Among the ectosomal asters, the large type, 20 \i in diameter, 

 with conspicuous centrum and many rays, is much more abundant. 

 The centrum is typically about one-fourth the total diameter, some- 

 times reaching one-third the total diameter. 



(6) The thin, brown, semifibrous layer in the deepest part of the 

 ectosome is not present. 



The specimen, as said, is imperfect. It is hemispherical and prob- 

 ably represents the upper part of a subspheroidal sponge, the lower 

 half of which has been torn away. Horizontal diameter 25 mm.. 

 No oscula discoverable. Surface smooth and entirely covered by a 

 thin layer of debris which obscures the pores. Color, very light 

 brown. 



Genus ECIONEMIA Bowerbank (1864). 



Ecionemia Bowekbank, 1S04, p. 173. — Sollas, 1888, p. 195 plus Psammaatra 



Soi.i.as. 1888. p. 174. 



The ectosome may or may not be sufficiently fibrous to constitute 

 a cortex. The larger triaenes supporting the dermal surface are 

 usually plagiotriaenes (sometimes orthotriaenes or dichotriaenes). 

 The microscleres include microrhabds which typically are minute 

 roughened strongyles forming a dermal layer. The euasters are 

 typically chiasters. rays tylote (tylaster) or not; the rays sometimes 



