Geological Society, 479 



niOCEEDINGS OF LEARNED SOCIETIES. 

 GEOLOGICAL SOCIETY. 

 November 22nd, 1899.— W. Whitaker, B.A., F.R.S., 

 President, in the Chair. 



The following communication was read : — 



' On some Remarkable Calcisponges from the Eocene Tertiary- 

 Strata of Victoria (Australia).' By George Jennings Hinde, Ph D 

 F.R.S., F.G.S. 



The greater number of the sponges described were discovered 

 by Mr. T. S. Hall, AI.A., of Melbourne University, in incoherent 

 detrital beds of Eocene age, in the southern part of Victoria ; a few 

 were picked out of some washings of fragmental polyzoa from 

 the same district and horizon, by Mr. B. W. Priest. Some of 

 the specimens are in an extremely perfect condition, and their 

 structural details are as distinctly shown as in recent sponges. 

 They are also of more than local interest in that they are the first 

 fossil forms described of a group of calcisponges, the Lithonina, 

 characterized by the peculiar aberrant forms of some of the spicules, 

 and the mode in which they are closely fitted and organically fused 

 together to form the skeletal mesh. This structure has, so far, only 

 been recognized in one recent species, Fetrostroma Schuhei, Doderlein, 

 from the Japanese Sea. 



The sponges are small, unattached, with a glassy, firm, resistant 

 skeleton, calling to mind that of siliceous Lithisfcida. They aro 

 built up of a great variety of s} icular forms, some are simple rods, 

 with three- and four-rayed spicules, similar to those in recent 

 calcisponges ; but the majority are aberrant four-rayed forms, with 

 three of the rays curved and with obtuse or expanded ends which 

 are clasped, and fused as well, to the surfaces of adjacent spicules. 

 The connected spicules form continuous anastomosing or radial 

 fibres resembling those in the fossil Pharetrones, to which they aro 

 in some other respects similar, and it is probable that the spicules in 

 the fibres of some members of this family were likewise organically 

 cemented together. The common Porosphienv. from the Upper 

 Chalk, generally regarded as Hydrocorallines allied to the recent 

 Milleponi, are also closely related to the above sponges, and the 

 Author hopes shortly to publish the evidence for their affinity 

 to this group. 



The Victorian sponges are placed in four new species, belonging 

 to three genera : two of these are new, the other, BacfroneUa, Hinde, 

 was founded on some peculiar calcisponges of Jurassic Age, now 

 known to be Lithonine in character. 



December 6th, 1899.— W. Whitaker, B.A., F.R.S., 

 President, in the Chair. 

 The following communication was read: — 



'On the Geology and Fossil Corals and Echinids of Somali- 

 land.' By Dr. J. W. Gregory, F.G.S. 



British Somaliland consists of a high plateau, of which the 

 northern scarp is separated from the Gulf of Aden by a belt of low 

 hills and plains known as the Guban. The southern plateau 



