November 27th, z<?o6.] PROCEEDINGS. xvii 



of Land and Freshwater Mollusca collected by Mr. 

 S. A. Neave in North-east Rhodesia." 



Specimens of the shells of a number of the species described 

 were exhibited. 



The communication standing in the name of Dr. F. W. 

 Gamble was postponed to the next meeting on December nth. 



Ordinary Meeting, December nth, 1906. 

 Mr. Francis Nicholson, F.Z.S., in the Chair. 



The thanks of the members were voted to the donors of the 

 books upon the table. 



Dr. F. W. Gamble presented a short communication on the 

 discovery by Biitschli of strontium sulphate as the basis of the 

 skeleton in certain Radiolaria (Acantharia). Up to the present 

 time the nature oi the Acantharian skeleton was a disputed 

 subject. Johannes Miiller, who first described it, regarded its 

 basis as siliceous. Haeckel subsequently carried out a series of 

 tests that seemed to establish an organic horny substance as the 

 chief component of the skeleton, and to this he gave the name 

 Acanthin. Since this analysis has been universally accepted, it 

 seems desirable to record Biitschli's results, which are both con- 

 tradictory to Haeckel's, and apparently conclusive from the 

 convergent and confirmatory outcome of the different tests 

 employed by him. Working with material brought back by the 

 German Antarctic expedition, and also upon Mediterranean 

 Acantharia, Biitschli has shewn that strontium sulphate is the 

 material of which the complex rods and spicules of these 

 Radiolaria are composed. This is the first time that strontium 

 has been described in animal tissues, and coincides with the 

 recent discovery of barium sulphate in certain other deep-sea 

 Protozoa (Xenyophophoridse). 



Professor F. E. Weiss, D.Sc, F.L.S., read a paper entitled 

 " The Parichnos in the Lepidodendraceae" 



Miss Katharine H. Coward, B.Sc, read a paper (com- 

 municated by Professor F. E. Weiss, D.Sc, F.L.S.) entitled, 



