REPORT ON THE MONAXONIDA. 



Vll 



It is worth our while to investigate in this place the treatment which the 

 Monaxonida, thus constituted by Zittel as a distinct group of sponges, have met with 

 at the hands of other recent authors. 



Commencing with Bowerbank, we find that his classification of sponges has the one 

 advantage of simplicity, though, based as it is almost solely upon the arrangement of 

 the skeleton, without any regard to the anatomy of the soft parts or to the forms of 

 the spicules (except as specific characters), it has led to the most absurd results and 

 has been followed by no one. Briefly, then, it is as follows:^ — 



Class Porifera. 



Order 1. Calcarea. 

 Order 2. Silicea. 

 Order 3. Keratosa. 



The " Silicea " and " Keratosa " are further divided into suborders (but these have 

 no names) and then straightway into genera. The Monaxonida are chiefly to be found 

 amongst the Silicea, being dispersed through five suborders ; but two genera, Clialina 

 and OpJilitaspongia, are relegated to the Keratosa. 



Gray took the field armed with a much more elaborate scheme, which cannot be 

 said to possess even the advantage of simplicity ; it was as follows :" — 



1. Spongiadse. 



2. Ceratelladae. 



3. Hirciniadce. 



Class Pcn-iphora. 



Subclass 1. P. Silicea. 



Section A. Thalassospongia. 



Subsection 1. Leiospongia. 



Order 1. Keratospongia. 



Families — • 



4. Dysideidae. 



5. Chalinidae. 



6. Phakelliadae. 



7. Halichondriadce. 



8. Polymastiadse. 



9. Ophistospongiadse. 



1. Suberitidse. 



Order 2. Suberispongia. 



Families— 

 2. Eaphiopboridae. 



3. Clioniadffi. 



1 Vide Men. Brit. Spong., vol. ii. p. xx. 



' The arrangement of the subclass Silicea here quoted, is to be found in Gray's paper— Notes on the Classification 

 of Sponges, in Ann. and Mag. Nat. Hist, ser. 4, vol. ix. p. 446, 1872. The Calcarea are not dealt with in this, Gray's 

 second, scheme, but his anangement of them will be found in his first scheme in Proc. Zool. Soc. Lond., 1867, p. 553. 



