Miscellaneous. 



67 



Subefitida;. 

 Uniradiatos without perceptible horny substance. 



Chlathridoe. 

 Network of horny fibres with imbedded obtuse spicules. 



EcJiispidce. 



Remeridce. 



Biradiates without percep- 

 tible horny substance. 



Network of horny fibres 

 with imbedded uni- or 

 biradiates and projecting 

 tubercular spicules. 



CJudcmiidce. 



Network of hortiy fibres with dense masses of coarse 



imbedded biradiates. 



Chalarchidie. 



Network of horny fibres with scanty, axial, extremely 

 delicate biradiates. 



Ceraospongias. 



The Chalarchidse and Chalcajnidae, at least the Australian forms, 

 are so diff'creut from each other, that for the sake of uniformity I 

 have preferred to divide the Chalinida) of authors into these two 

 main sections. 0. Schmidt's numerous families of Chaliuidae would 

 in this scheme appear as subfamilies. 



Among the Chalarchidae we find sponges resembling Euspongia, 

 Cacos23on(/ia, and Spongelia. Possibly therefore the pedigree of the 

 Chalarchidne may be polyphyletic, different members of the family 

 being descended from the above-mentioned horny sponges. 



I will here mention a peculiar intermediate form which combines 

 characters of the Chalarchidas with those of SpongeUa. The skele- 

 ton of this sponge consists of a ladder-like network of horny fibres. 

 The radial main fibres are entirely filled with sand, and bear no 

 spicules. The tangential uniting fibres, which are not much 

 weaker and do not anastomose with each other, are entirely filled with 

 axial, evidently self-formed biradiates, and bear no foreign bodies. 



The Echispidse for the most part coincide with Gray's Echino- 

 nemata. 



