Geological Society. 495 



and experimental psychology, and requires the solution of a com- 

 plicated transcendental equation. The tables obviate this. 



The Tables will be of greatvalue to psychologists and others who 

 use modern statistical formulae, and have not had the opportunity 

 to acquire the mathematics that will enable them to estimate the 

 significance of their results, as the tables enable the probable 

 errors (which mean troublesome mathematics) to be read off. 



Considering the great amount of labour in calculating the tables 

 and the expense in printing and publishing them, the price of the 

 book is very reasonable. It is hoped that Prof. Pearson will be 

 able in the near future to fulfil his promise to issue a second and 

 larger edition of this work. 



LVIII. Proceedings of Learned Societies. 

 GEOLOGICAL SOCIETY. 

 [Continued from p. 416.] 



June 23rd, 1915.— Dr. A. Smith Woodward, F.R.S., President, 

 in the Chair. 



HPHE following communications were read : — - 



1. ' On a New Eurypterid from the Belgian Coal Measures.' 

 By Prof. Xavier Stainier. 



2. ' On a Fossiliferous Limestone from the North Sea.' By 

 Eichard Bullen Newton, F.G.S. 



3. ' The Origin of the Tin-Ore Deposits of the Kinta District, 

 Perak (Federated Malay States).' By William Eichard Jones, 

 B.Sc, F.G.S. 



Certain tin-ore-bearing clays and boulder- ck/ys occurring in 

 the Kinta district have been described by Mr. J. B. Scrivenor, 

 Government Geologist, F.M.S., as being of glacial origin, and 

 the tin -ore which they contain as having been derived from 'some 

 mass of tin-bearing granite and rocks altered by it, distinct from 

 and older than the Mesozoic Granite ' (that is, than the granite 

 now in situ in the Kinta district). These stanniferous clays and 

 boulder-clays are stated to have furnished a more valuable horizon 

 on climatic evidence than can be afforded by limited collections of 

 fossils in rocks far removed from Europe, and have been correlated 

 with the Talchirs of India and mapped as Older Gondwana rocks. 



It would be difficult to overestimate the importance of the 

 origin of these clays in a country where, on the one hand, they 

 yield a very important part of the world's output of tin-ore, 

 and where, on the other, they have been used as the horizon on 

 which to base the geological age of rocks which cover about a 

 third of the surface of the Malay Peninsula. If of glacial origin, 

 a vast tin-field remains to be discovered. 



