

BY E. P. HALLMANNT. 771 



unmistakable — proves conclusively that this view is erroneous. 

 Thus my suggestion that Clathriopsamma reticulata Lendenfeld 

 might be included in the genus Rhaphidophlus (now Tenacia) 

 becomes untenable, and I now propose to recognise the genus 

 Clathriopsamma as distinct. 



The species known to me which I consider to belong to 

 Tenacia are those (excepting Clathriopsamma reticulata and 

 very probably also Clathria spiculosa Dendy) of which I have 

 already furnished a list (6, p. 227) in connection with my 

 previous remarks on Rhaphidophlus ; and, in addition, Rhaphi- 

 dophlus filifer var. cantabrica Orueta (15), and Clathria typica 

 var. porrecta Hentschel (10), of whose existence I had not, at 

 that time, information. Since then, also, have been described 

 by Hentschel (10) Clathria nuda and Clathria frondifera var. 

 dichela; and so far as can be judged from their descriptions and 

 figures, it seems to me very probable that they too belong to 

 Tenacia. Whether Tenacia arcifera 0. Schmidt is another 

 species properly to be included in the genus, I am unable 

 to say, not having seen its description . 



Genus Clathriopsamma Lendenfeld . 



Definition.- — Desmacidonidae in which the microscleres are 

 isnr-helae palmatae and rhaphidiform toxa (the latter typically 

 indistinguishable from long slender oxea, and in part occurring 

 in dragmata) ; in which the main skeleton is an irregular reticu- 

 lation of spiculo-spongin fibres, of which the main (if not also 

 the connecting) fibres are cored by foreign bodies and by 

 smooth (principal) styli, and are echinated by small aeantho- 

 styli; and in which the auxiliary megascleres, occurring both 

 dermally and scattered interstitially, are smooth slender styli or 

 tylostyli, typically provided on the basal extremity with a cap 

 of minute spinules. 



Type, C. reticulata Lendenfeld ; the only species. 



Of the two species which Lendenfeld (6, p. 227) referred to 

 his genus Clathriopsamma, the first-described, C. lobosa, is now 

 known to be identical with Wilsonella australiensis. The other, 

 C. reticulata,— of which I have already furnished a brief re- 

 'IcM-ription in a former paper (6, p. 177), — possesses char- 

 acters which appear to me sufficiently distinctive to warrant our 

 retention of the genus Clathriopsamma for its reception. 



