206 LIVERPOOL BIOLOGICAL SOCIETY. 
referred to by Mr. Higgin under the name Ophlitaspongia 
sertata, under the genus Clathria, Schmidt. Having found 
this form in profusion at Puffin Island, April, 1889, and 
at Port Erin, Easter, 1889 and 1890 (at both places for 
the first time), I am able to give now a further account of 
its systematic position. 
I may use the same words in regard to this species 
which were used by Ridley and Dendy* about Clathria 
znanchorata: ‘* Although it possesses no chele, yet this 
species agrees so closely with the genus Clathria in other 
respects that we have deemed it advisable to include it in 
that species, it is perhaps a form that once possessed iso- 
chelate microsclera and has now lost them.’ And this 
Clathria imanchorata is the only Desmacidonid sponge 
which forms an exception to Ridley and Dendy’s defini- 
tion of the family Desmacidonide. Their definition runs 
as follows (page 62):—‘‘ Desmacidonide : Megasclera of 
various forms, usually monactinal. Microsclera always 
present and always including chele.’’ Then they add in 
a footnote: ‘‘ We have included one or two species with- 
out chele on the supposition that they have had them and 
subsequently lost them.” I would prefer the exception 
to be included in the definition proper of the family, espe- 
¢ 
cially as we do not know whether their “ supposition ” 
corresponds to phylogenetic facts. For that reason I am 
inclined to accept rather Lendenfeld’s+ definition of the 
Desmacidonide: ‘‘ Cornacuspougiz with a supporting 
skeleton composed of spiculiferous, often echinated fibres. 
Generally with chele in the ground substance. If chele 
are absent, the fibres are echinated by projecting spicules.” 
* Ridley and Dendy, ‘‘ Report on the Monaxonida collected by H.M.S. 
* Challenger,’” p. 150. 
+ R. v. Lendenfeld, ‘‘ Descriptive Catalogue of the Sponges in the Aus- 
tralian Museum, Sydney,” p. 210. 
