Reports and Proceedings — Mineralogical Society. 28-3' 



in Cranham Wood are given in connection with the location of 

 the anticlinal axis. The exact location of the anticlines and 

 synclines of the Inferior Oolite rocks in the Cotteswolds, where 

 sections are numerous, may afford some important working hypo- 

 thesis for unravelling the structure of the Yale of Gloucester, where 

 excavations are few. 



3, " Description of a Species of Heterastrcea from the Lower Eha9tic 

 of Gloucestershire." By Eohert F. Tomes, Esq., F.G.S. 



The specimen described was obtained by Mr, L. Eichardson from 

 Lower Ehaetic beds at Deerhurst (Gloucestershire). It occurred 

 a little way above the bone-bed ; it is specifically and generically 

 new to the Ehaetic, and it displays Jurassic relationships. It differs 

 from the several Liassic species in the small size of the corallum and 

 of its calices. Eemarks on some other Madreporaria from the Eh^tic 

 and from the basement of the Lower Lias are appended. It has 

 always been the author's opinion that the Sutton Stone containing 

 Ehsetic Madreporaria should be classed as Eheetic ; indeed, he believes 

 that it is really Upper Eheetic ; and in view of the very close affinity 

 of its organisms with those of the Lower Jurassic, and bearing in 

 mind the great importance of the Ammonite zones as a means of 

 classification of the Liassic deposits, he asks whether the zone of 

 Ammonites planorbis should not be taken as the bottom of the Lias. 



III. — Mineralogical Society, March 24th. — Dr. Hugo Mtiller, 

 F.E.S., President, in the chair. Dr. A. Hutchinson described 

 some remarkably interesting experiments which he had made on 

 the diathermancy of antimonite. A cleavage flake of antimonite 

 0-29 mm. thick and 20 sq. mm. in area, perfectly opaque to light, 

 was placed between cross nicols and exposed to the radiation from 

 a limelight. The plate was somewhat transparent to radiant heat, 

 and the amount transmitted was measured by Boys' radiomicrometer. 

 No heat was transmitted when the planes of symmetry of the 

 crystal coincided with the planes of polarisation of the nicols, but 

 the maximum effect was produced on the radiomicrometer when 

 the plate was turned through 45^^ in its own plane. The results 

 so far arrived at are in harmony vrith the orthorhombic symmetry 

 attributed to antimonite. Mr. J. B. Scrivenor described the 

 occurrence of magnetite in the Upper Bunter Sands at Hinksford, 

 near Stourbridge, and of anatase in the Trias of the Midlands. 

 The crystals of magnetite, measuring on an average '067 mm., were 

 in cubes or octahedra. The mode of occurrence and the presence 

 of a single set of striations parallel to the cube edge, suggest that 

 they are pseudomorphous after iron pyrites. The anatase, in 

 crystals from -025 to '06 mm., is found more abundantly in 

 the Keuper than in the Bunter. The crystals show the forms 

 (111) and (001), and according to the predominance of either form 

 are pyramidal or tabular in habit. Many of them are attached 

 to leucoxene derived from ilmenite or sphene. The anatase has 

 been formed in situ, after the deposition of the sandstone, as 



