332 Mr. A. Dendy on the 



possess only diactinal megasclera and no microscleva ; and 

 Dr. von Lendenfeld, as we have seen, himself describes them 

 as being " ohne differente Fleischnadeln." What, then, are 

 his " Toxins, Sigma, Aniphitoxius, Spirula, Spirobacter," if 

 not '' differente Fleischnadeln " ? and how can he possibly 

 include such forms as possess these spicules amongst the 

 Chalininee ? 



It has been demonstrated again and again by various 

 authors that the mere possession of a large amount of spongin 

 in the skeleton is not a sufficient guide to the systematic 

 position of a sponge ; and to found a group on this character 

 alone is totally out of accord with the present state of our 

 knowledge. Spongin is enormously developed in many of 

 the Desmacidonid^, and it also occurs abundantly in the 

 Heterorrhaphidse and Axinellidse. 



Amongst the Heterorrhaphida3 the subfamily Grelliinge 

 (Kidley and Dendy) is characterized by the presence of diactinal 

 megasclera and microsclera in the form of sigmata or toxa. 

 It contains three genera, GelUus, Gray, GeUiodes, Ridley, and 

 Toxochalina, Ridley. GeJliodes differs from Oellius solely in 

 the possession of a larger proportion of spongin in the skele- 

 ton ; and yet Dr. von Lendenfeld removes GelUodes from the 

 Gelliin93 and places it amongst the Chalininae ; and he does 

 the same with Toxochalina, which also happens to possess 

 much spongin. If he thinks that the characteristic micro- 

 sclera (sigmata and toxa) of these two genera are not suffi- 

 ciently "differente"* to justify their separation from the 

 Chalininffi then the whole family Heterorrhaphidge must, for 

 him, fall to the ground, for none of the genera therein included, 

 except Vomerula and Hamacantha, have more " differente " 

 microsclera ; but he accepts the family in his classification. 

 It is clear that GelUodes must go where GelUus goes, the mere 

 presence of a greater or less amount of spongin cannot in this 

 case be regarded as of more than generic value ; but no one 

 would think of calling GelUus a Chalinine sponge. 



In fact it is obvious that we must depend on spicules rather 

 then on spongin for guides to classification. In putting such 

 forms as GelUodes and Toxochaliyia amongst the Chalininas Dr. 

 von Lendenfeld does away at once with all distinction between 

 the Homorrhaphidse and Heterorrliaphida3 ; and under such 

 circumstances he has no business to retain these two groups in 

 his system. 



* On p, 797, however, tlie "subj;enus" Toxochalina is defined thus: — 

 •' Phylosiphoninse mit ditferenten Fleischnadeln (Toxii)," which scarcely 

 seems in accordance with the previous statement that the Homorrhaphidae, 

 as a family, are " ohne differente Fleischnadeln " (p. 761). 



