278 Mr. H. J. Carter on the Nomenclature o/" Clathrina. 



be found to be only "bideutate" — that is, whether in all more 

 or less of a central fluke might not be detected. 



It is worthy of remark, when looking at the illusti-ations of 

 Ectyon sjmrsus and Acarnus innominatus in the plate, that, al- 

 though belonging to different orders, both are armed sponges — 

 that is, characterized by the projection of spicules from the 

 outside of the skeleton into the interstices ; while the skeleton 

 oi Ectyon sparsus is formed of horny fibre, and that of Acarnus 

 innominatus of large spicules almost alone respectively, show- 

 ing the value of the latter distinctions over the former simila- 

 rity, in the matter of classification. 



On the Nomenclature o/" Clathrina, Gray. 



As regards the multiplication of synonyms, which is the 

 bane of natural history. Dr. Bowerbank has chosen new names 

 for nearly all Dr. Johnston's sponges. Dr. O. Schmidt new 

 ones for almost all Dr. Bowerbank's, and my friend Dr. Gray 

 new ones for the species of both. 



Much of this has arisen from the want of adequate illustra- 

 tions of the entire sponges, in the first place, combined with 

 microscopical details — an omission which characterizes in part 

 Dr. Johnston's work of 1842, where the absence of the latter 

 is more excusable, because the value of the microscope in such 

 inquiries had hardly become known when his book was under 

 preparation, but certainly not in Dr. Bowerbank's ' Mono- 

 gi'aph ' of 1864-66, wherein both illustrations and details are 

 wanting — a deficiency which Dr. Bowerbank informs me he 

 is about to supply ; but, unfortunately, the time is past, the 

 names are multiplied, and Dr. O. Schmidt's works on the 

 Sponges of the Adriatic Sea, the coast of Algiers, and the 

 Atlantic Ocean have deservedly become the chief sources of 

 reference for those engaged in the study of the Spongiadas. 



There is a calcisponge which grows in flat spreading patches 

 over the lower surfaces of the rocks here as plentifully as, if not 

 more so than, any other kind or species. At first it looks like 

 a delicate piece of fine white lace ; but on nearer inspection, 

 especially with a lens, it may be observed to consist of a dense 

 reticulation of anastomosing tubular thread, which finds its 

 vents on the summits of small papillary eminences of the 

 same structure, from which the tubulation, a little increased 

 in size at these points, branches off to the divisions of the 

 sponge which the vents or oscules respectively di-ain. 



For this sponge Montagu, in 1818 (Mem. Werner. Soc. 

 vol. ii. p. 116), proposed the name of Spongia coriacea^ with 

 the following description : — " The fibres that constitute this 



