502 Geological Society. the lateral ventral plates ; the two or three posterior segments of the body enlarged and tuberose ; anal styles small, not used in walking. 1. Gonibregmatus Cumingii, Newport. Greyish ash-colour ; frontal segment very convex, rounded poste-riorly ; mandibles blackish ; labium smooth ; all the segments of the body very short, convex ; dorsal surface with numerous irregular lon-gitudinal sulci ; antepenultimate segment with the dorsal and ventral plates atrophied ; anal styles slender, with their basilar internal mar-gin carinated; anal scale convex, subcordate, posteriorly rounded with two thin marginal plates ; legs 161 pairs, naked, claws black. Length 4j to 5 inches. From the Philippine Islands. Mr. Cuming. In the collection at the British Museum. I have never seen the Geophilus Walckenari of Gervais, but from the description given of that species I strongly suspect that it ought to be included in this genus. PROCEEDINGS OF LEARNED SOCIETIES. GEOLOGICAL SOCIETY. May 4, 1842. — Read " A Postscript to the Memoir on the occur-rence of the Bristol Bone-Bed in the neighbourhood of Tewkes-bury," by Hugh Edwin Strickland, Esq., F.G.S. Since the reading of the former communication (vol. x. p. 147), Mr. Strickland has ascertained that the bone-bed occurs at least ten miles further north, or at Defford Common, in Worcestershire, making a total range of 104 miles. At this locality are some old salt-works belonging to the Earl of Coventry, and the shaft, which was sunk about seventy years ago to the depth of 175 feet, was emptied a few months since of the brine with which it is wont to overflow. At the bottom of the shaft, which descends through the lias into the grey marl of the triassic series, but without reaching the red marl, is a tunnel that follows the dip of the strata for about 160 yards. The shaft, Mr. Strickland says, consequently intersects the horizon of "the bone-bed," and among the rubbish thrown out, he found considerable quantities of the peculiar white sandstone with bivalves (Posidonomya), shown in his former paper to repre-sent in Worcestershire the bone-bed of Aust and Axmouth ; but he also found specimens of the sandstone charged with the same description of teeth, scales and coprolites so abundant at Coomb Hill and the localities just mentioned. The occurrence of an abundance of pure salt water within the area of lias, Mr. Strickland says, is an interesting phenomenon, and for a solution of it, he refers to Mr. Murchison's Account of the Geology of Cheltenham, p. 30. June 29. — " On the minute Structure of the Tusks of extinct Mastodontoid Animals." By Alexander Nasmyth, Esq., F.G.S. The author, at the commencement of his memoir, acknowledges his obligations to Dr. Grant for having first called his attention to the
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