568 Reports and Proceedings — Geological Society of London. 



more large radial tubes, and the floor of each interspace towards the 

 centre is made up of the minute chamberlet structure, the open- 

 ings of which communicate only with the interspace beyond. The 

 labyrinthic structure sometimes stretches across the interspaces, and 

 the radial tubes communicate at their sides with the labyrinthic 

 chamberlets of the lamellas forming the floor and roof of the inter- 

 spaces. The continuity from the centre of the body to the circum- 

 i'erence is thus defective, and the body consists of radial tubes and 

 of a labyrinthic structure of a cellular and semicellular character. 



The author maintained that the two structures were intrinsically 

 different, and he also indicated a difference in the mineral condition 

 of the fossils, Parlceria being always phosphatic, whereas no phos- 

 phate of lime could be detected in StoUczharia. 



2. " On the Elasticity- and Strength-constants of Japanese Eocks." 

 By Thomas Gray, Esq., B.Sc, F.K.S.E., and John Milne, Esq., F.G.S. 



In this paper the authors described the results of some experi- 

 ments made to determine the elasticity-constants and strength 

 against rupture and crushing of a few of the commoner Japanese 

 rocks, their chief object being to obtain data for calculating the 

 theoretical velocities of earthquake- wave transmission. The rocks 

 submitted to experiment were a grey granite, a pure white crystal- 

 line marble, a greyish-green soft tuff, a mottled clay-rock, and clay- 

 slate. 



Young's moduli were determined by the bending of solid cylinders 

 of the rocks in an apparatus described and figured ; the deviations 

 produced were read by means of the reflection from a mirror, which 

 magnified them more than 200 times. The process for determining 

 the rigidity was also described and illustrated by a figure ; and the 

 experiments in crushing were made upon columns of stone by means 

 of a Bramah press. In experiments on the rupture of the columns 

 there was no marked deviation from the proportionality of strain to 

 stress up to the breaking-point, except in the case of the marble. 

 In crushing, the authors obtained considerable lower moduli than 

 those quoted in tables for similar rocks ; and, as their experiments 

 were performed upon columns about three times as long as their 

 diameter, they repeated them upon columns of marble varying in 

 length from one half to six times the thickness. The results seemed 

 to show that the short specimens were the weakest ; but there was 

 little difference. The authors give the formulse by which they 

 worked out the results of each series of experiments, and bring 

 together the mean results in a tabular form. 



3. "The Glacial Deposits of West Cumberland." By J. D. 

 Kendall, Esq., C.E., F.G.S. 



The author gave a biief sketch of the physical geography of the 

 district and of the distribution of the more remarkable and easily 

 recognized varieties of rock. The glacial deposits, viz. Boulder- 

 clays, sands, and gravels, occupy mainly the area of low ground 

 skirting the hills, extending upwards to a height of about 500 feet 

 above the sea ; above that contour-line they only occur in isolated 

 patches or tongae-like prolongations up valleys to elevations occa- 



