306 REVISION OF THE MONAXONID SPONOES, i., 



the British Museum, a tiny piece labelled "Suberitella lajca, 

 Port Jackson," the spicules of which correspond to the 

 description of those of the so-called Suberites doniuncula ex- 

 actly in every way, excepting that they never attain to more 

 than 300 /x in length. It would be interesting to know whether 

 this sponge agrees with the description of the species in ques- 

 tion in other respects ; if it does, one would be justified, I 

 think, in identifying the latter (as recorded from Port Jack 

 son) with it. 



Plectodendron elegans. (PI. xviii., fig.l). 



In the pattern of its skeleton and the form of its spicules, 

 Phctodendron degans bears an almost exact resemblance to a 

 species, represented in the Australian Museum by two speci- 

 mens from N.W. Australia, which I unhesitatingly identify 

 as Caulospongia verticillata Kent(22): as the two species are 

 congeneric, and each is the type of its genus, Phctodendron 

 is, consequently, a synonym of Caulosjmngia. Kent described 

 also, from an unknown locality, CaidosiJongia plicafa; and 

 Bowerbank (3a) described, at a later date, as new, from 

 A^'estern Australia, (liaJnia verficdlafa; — both of which 

 species appear to me to be identical with CauJos'pongia verti- 

 cdlata. In spite of these several descriptions of its type- 

 species, the genus Caulospongia, for some reason, never gained 

 recognition, and since the time of its erection (1871) has 

 apparently received no other mention than that by Vosmaer'50), 

 who lists it among the genera, the systematic position of which 

 " absolut unsicher oder unbekannt ist," and that by Topsent(46), 

 who quotes it as a synonym of Semisuherites Carter(^): but for 

 this identification, there appears to be no foundation. 



The main skeleton, in the several species of Caulospongia 

 known to me, is a very irregular, small-meshed reticulation of 

 spicules and spiculo-spongin fibres, some of which fibres are 

 stout and densely multi-spicular : the pattern of the skeleton 

 is such that, if the stouter fibres were absent, one might 

 describe it as confusedly renieroid. In C . elegans, spongin is 



