1 42 Correspondence — Bibliographer. 



other EhEetic mollusca ; and a range-table is appended of the 

 commonest mollusca that occur at Sodbury and Stoke Gififord. 

 The reptiles, amphibia, and fishes referred to are all known species. 

 A general account is given of the distribution of the Bone-bed 

 in the Bristol district. In Somerset, except at Eiuborough and 

 Watchet, no true Bone-bed has been recorded ; in the district 

 immediately north of Bristol there is a single, well-marked Bone- 

 bed at the base of the Black Shale series, or very slightly above it ; 

 while in the Gloucester district the principal Bone-bed tends to lie 

 at a greater distance from the base of the Black Shales. For these 

 reasons, the authors think that the principal Bone-beds in the 

 various sections cannot be i-egarded as homotaxial equivalents. 



n. — MiNKRALOGic^L SociETY, Feb. 2iid, 1904. — Dr. Hugo Miiller, 

 F.R.S., President, in the chair. Mr. Harold Hilton contributed 

 a paper on the Gnoraonic net. This net consists of lines giving 

 equal longitudes and latitudes for every ten degrees on a plane 

 touching a point on the equator, the former being hyperbolae and 

 the latter straight lines. The author pointed out how the net could 

 be used for the graphical determination of angles between poles on 

 the sphere. — Mr. G. T. Prior described a new sulphostannite of lead 

 from Bolivia, to which he gave the name Teal lite, in honour of the 

 Director of the Geological Survey. The mineral in its graphite-like 

 appearance resembles franckeite and cylindrite, but differs from 

 them in not containing antimony. It has the simple formula 

 Pb Su S.„ and is orthorhombic with angles c (001) A o (111) =62°, 

 c (001) 'hp (221) = 75°, and m (110) A m"' (110) = 86°. It has 

 a perfect cleavage parallel to c (001), and a specific gravity of 6'36. 

 In connection with the investigation of this mineral, new analyses 

 were made of franckeite and cylindrite. — Mr. W. F. Ferrier gave an 

 account of his discovery of deposits of corundum in Canada; and 

 Professor H. A. Miers described a visit to the Rashleigh Collection 

 of Minerals now deposited in the Museum of the Royal Institution 

 of Cornwall at Truro. 



aoE-iazESiPOiTnDJEisrcjs. 



MR. A. G. M. THOMSON'S BOOK ON THE OLD RED SANDSTONE. 

 Sir, — Without dissenting from the opinions expressed by your 

 Reviewer (this vol., p. 84, Feb.), may I suggest that the expression 

 of them is not quite fair ? You give the name of John Leng & Co., 

 Dundee, as that of the publishers, and you " can only wonder why 

 such a work has been published." I have, however, the highest 

 authority for stating that the work has not been published, but 

 distributed privately, as a gift by the author, while Messrs. Leng 

 are only the printers. It seems to me that the proper way to treat 

 unpublished communications is to ignore them : if such a course be 

 agreeable to the author, well and good ; but if it is not agreeable to 

 (Jiitn — so much the better ! Bibliographer. 



