30 



PAPER BY COLONEL COX ON SPONGID.E. 

 March 3rd, 1880. 

 Colonel Cox said : — The great improvement which has 

 (comparatively speaking) recently taken place in the construction 

 of microscopes, both as regards penetrating power, more perfect 

 illumination, clearer definition of outline and advanced mechani- 

 cal arrangement, has led to the discovery of the life history of 

 ^ome of the lowest types of organised beings (hitherto unknown 

 to science) and to our now reading, with a more accurate know- 

 ledge, many of those important physical changes brought about 

 by their agency, and which daily play no very inconsiderable 

 part in the topography of the Globe. 



Thus, for instance, the microscope has made us acquainted 

 with a minute class of organised beings called Polyps, some of 

 whicli construct the great coral reefs of equatorial oceans, in 

 time to be formed into islands, soon to be clothed with luxuriant 

 -vegetation, and rendered fit for human habitation — whilst 

 another, the spongidas, teem in the shallows between high and 

 low water mark as well as in the great depths of the ocean, the 

 latter living we may almost say irrespective of the influence of 

 ■climate and light and the astounding pressure of some twelve 

 thousand feet of water. 



Polypoe or Zoophytes, animal plants as they are sometimes 



called, are divided by jMantel into three classes. 

 Porifera or Spongidas — Animals whose dwellings are per- 

 forated by tubes or canals to allow of a free current of 

 water frotn which the Polypoe draw their nourishment — 

 passing through the mass of sponge, tentacles absent : 

 Polipifera. — Coral animals. — Groups of Polyps armed with 

 tentacles, permanently united by a common integument, 

 each animalcule having an independent existence; 

 Bravozoa. — MoUuscan animals such as the Flustra. 

 IMy' object this evening is not to speak of Zoophytes in 

 general but to confine my remarks simply to the order Spongidce 

 and in that class only to the Keratosa. 



The Porifera or Spongidse are divided into the 



Keratosa. — Sponge having a horny or fibrous habitation — 



such as the sponge of commerce. 

 Calcarea. — Habitations generally composed of lime as in the 



Grantia. 

 Silica. — Homes built up of silica or flint as the Euplectella 



Speciosa. 

 Before referring to the fossil remains of sponges of a bygone 

 period, revealed to us by the workings of quarries, gravel pits 

 and the detritus of disintegrated rocks and composing the 

 shingle of our sea beaches, I have thought a short description of 

 •a sponge would render my remarks on the fossil Fauna of this 

 order more intelligible. 



The Spongia Communis or Sponge of Commerce I have 

 therefore selected to illustrate the general character of the 



