SILICIOUS AND HORNY SPONGES WILSON. 463 



The nearest relative of this remarkable sponge seems to be the 

 equally remarkable little form, PJeromit tiwbinatum, dredged by the 

 Challenger off one of the Fiji Islands and described by Sollas (1888, 

 p. 312) as the representative of a new family, the Pleromidae. The 

 simple character of the desma, the shape of which often suggests a 

 rib, is noteworthy in Cosfifer. The spicule resembles the rodlike 

 young stage of monocrepid desmas in general, more especially in 

 such a species as SclerUoderma paecardi O. Schmidt (1879, pp. 9, 

 28, pi. 2, fig. 3). 



Family SCLERITODERMIDAE. 



Rclcritodermidae Hollas, 1S8S, p. 315. 

 ScJerit Oder mat idae Lendenfeld, 1003, p. 141. 



"With special ectosomal megascleres having the character of 

 rhabds (tylostyles, styles, tylostrongyles, strongyles). Desma is 

 monocrepid. Microscleres when present are sigmas. 



Lendenfeld (1903, p. 141) accepts Sollas' family comprising the 

 two genera Scleritoderma O. Schmidt and Aciculites O. Schmidt. 

 Sollas' designation of the rhabds as microstrongyles is properly 

 abandoned but Lendenfeld's reference to them as amphistrongyles is 

 not apt. 



Assignable to the family and described since Lendenfeld's synopsis 

 (1903) is Aciculites orientalis Dendy (1905, p. 101) from Ceylon. 

 Regarding Microscleroderma Kirkpatrick and Taprobane Dendy, 

 see appendix to Leiodermatiidae. 



Genus ACICULITES O. Schmidt (1879). 



Aciculites O. Schmidt, 1870, p. 20. — Lendenfeld, 1003. p. 143. — Dendy, 

 1005, p. 101. 



Scleritodermidae without microscleres. 



Dendy (1905, p. 101) would place the genus in the Leiodermatiidae. 



ACICULITES CILIATA, new species. 



Plate 43, nsr. 7 : plate 51, flgs. 2, 3. 



Station D535G. one specimen. The sponge is a thick walled stony 

 cup more or less conical in shape but asymmetrical. Greatest hori- 

 zontal diameter 53mm., height 35mm., wall about 10mm. thick. 

 Latero-inferior surface separated from surface of cavity by a nearly 

 flat margin. 10mm. wide, which faces upward and outward. Color 

 of surface, brown; interior, lighter. In the marginal region of the 

 cup numerous small canals, a fraction of a millimeter wide, lying 

 just below and parallel to the dermal membrane, may be seen radiat- 



