Geological Bociefy, 509 



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. — " Notice on the discovery of the Remains of Insects in 

 the Lias of Gloucestershire, with some remarks on the Lower Mem- 

 bers of this Formation." By the Rev. P. B. Brodie, F.G.S. 



The lower beds of the lias, in which these organic remains occur, 

 are extensively developed in the neighbourhood of Gloucester and 

 Cheltenham, and occupy the greater part of the vale. In the upper 

 j)art of the lower beds, in a hard blue limestone, was found the ely- 

 tron of a coleopterous insect of the family Bupi-estidce, apparently a 

 species of Ancylochelra of Escholtz. This was the only fossil of the 

 kind met with by Mr. Brodie in tliis portion of the lias. With this 

 exception, the numerous fossil insects he has obtained occur in the 

 bottom parts of the lower beds near the base of the lias, which are 

 seen at several points in the neighbourhood of Gloucester. At 

 Wainlode Clift^, the lower beds of lias, resting on red marl, form a 

 bold escarpment on the south bank of the Severn, and afl^ord the 

 following section in descending order : — 



1. Clay: 3 ft. 



2. Blue limestone, with Ostrea, &c. (the "bottom bed"): 4 in. 



3. Yellow shale with fucoid plants: 6 in. 



4. Gray and blue limestone, termed by Mr. Brodie " insect lime- 

 stone " from its characteristic fossils, passing into yellow shale 

 above, Avhere it is nearly white, and has the aspect of a fresh- 

 water limestone : 3 to 5 in. 



5. Marly clay: 5 ft. 3 in. 



6. Hard yellow limestone, with small shells like Cydas, plants and 

 Cypris : 6 to 8 in. 



7. Marly clay: 9 ft. 6 in. 



8. Bed with fucoid bodies : 1 in. 



9. Shale : 1 ft. 6 in. 

 10. Pecten bed: 4 in. 



