524 Geological Society. 



Between three and four miles north of Ramsey, the beds of this 

 deposit occasionally exhibit a very remarkable concretionary struc- 

 ture. The sand has here been cemented into masses, which are ex- 

 tremely hard, and even sonorous when struck, though the sand in 

 which they are imbedded is perfectly loose. The cementing ingre- 

 dient, which the application of acid proves to be carbonate of lime, 

 seems to have been influenced in its operations partly by the planes 

 of stratification, and partly by the direction in which the sand has 

 been originally drifted by currents. In the former case the concre- 

 tions are in the form of flat tabular masses parallel to the stratifica- 

 tion, often mammillated on their surfaces, or perforated obliquely by 

 tubular cavities. In the latter case they assume a subcylindrical 

 or spear-shaped form, and occur parallel both to the stratification 

 and to each other. A pebble is frequently attached to the larger 

 end of the concretion, which springs from it as from a root, to the 

 length of a foot or more, and gradually terminates in an obtuse flat- 

 tened point. All these varieties are sometimes combined together 

 into vast clusters of several tons weight, resembling masses of sta- 

 lactite, the component portions being nearly parallel to each other. 

 Mr. Strickland supposes that currents of water (or possibly of wind, 

 operating during ebb tide), flowing in a certain direction, may have 

 disposed the sand in ridges parallel to that direction, and the car- 

 bonate of lime may have afterwards been attracted into these ridges 

 in preference to the intermediate portions. This view is confirmed 

 by the fact, that these concretions have frequently a pebble attached 

 to the larger end, as though it had protected a portion of sand from 

 the current, and caused it to accumulate in a ridge on the lee side, 

 a circumstance which may frequently be observed where sand is 

 drifted by the wind or water. 



Nov. 30, 1842. — " On the Bala Limestone." By Daniel Sharpe, 

 F.G.S. 



interior of the shell. Outer lip with about eight internal marginal denticles ; 

 no rib at the back. Total length, 1 inch 8 lines ; first volution, 8 lines ; 

 breadth, 9 lines ; angle of spire, 40°. 



"3. Fusus Forbesi, Strickland, 1843. Fusus nov. sp. Forbes, Malacologia 

 Monensis, pi. 3. f. 1. Middle-sized; volutions about six, slightly rounded, 

 suture distinct; ribs, eleven on first volution, straight, rounded, smooth 

 (perhaps from attrition) ; interstices concave, and hardly wider than the 

 ribs. First volution with about fifteen, and second with about seven distinct, 

 rather irregular spiral stria?, of which those on the first volution are alter- 

 nately large and small. They are only visible in the interstices of the ribs. 

 Aperture ovate, double the length of the canal, which is straight, and rather 

 oblique to the left. Pillar-lip smooth, with one obscure denticle at the pos- 

 terior end. Outer lip with about ten small linear denticles within, conti- 

 nued a short way into the mouth, and a well-marked external rib remote 

 from the margin. Total length, 1 inch 3 lines ; first volution, 7 lines ; 

 breadth, 8 lines ; angle of spire, 43°. 



" Obs. This species belongs to a group of Fusus which seems closely allied 

 to Nussa. First described by Mr. E. Forbes, from a worn specimen found 

 on the coast of the Isle of Man, and supposed by him to be an existing spe- 

 cies, but the discovery of additional specimens in situ proves it to be a 

 genuine fossil." 



