of the Great Oolite at Minchinhampton. 19 



4 species ; Pleurotoma 1 ; Hippocrenes, a group of winged shells differing 

 from the Rostellaria of the recent period, 10 species: Fusus, or a group 

 at least belonging to the Furince, 4 species. 



This extreme paucity of the Cephalopoda, taken in connexion with the 

 occurrence of numerous genera and species of carnivorous univalves, is a 

 remarkable circumstance. We know that previously throughout the lias 

 and inferior Oolite the Cephalopoda reigned supreme amongst the mollus- 

 cous tribes. Subsequently also the Oxford clay and Portland Oolite 

 contained them in nearly equal profusion. With these facts before us, the 

 inquiry naturally follows, — Were there any peculiar circumstances con- 

 nected with the mineral character of the deposit at the locality in question, 

 and what was the probable depth of the sea over the shelly beds ; since we 

 find here zoophagous tribes differing from those of warm seas at the present 

 time not very materially either in number or in their generic affinities? 

 First, with regard to the nature of the deposit, or at lea*t ihe more shelly 

 portions of it : — In the planking and Weatherstone beds we find heaps of 

 broken shells piled diagonally, the bivalves rarely having both valves in 

 apposition j with these are fragments of wood, crabs' claws, joints of 

 Apiocrinite and Pentacrinite, ossicula of Ophiura, palates and teeth of 

 fishes, small bouldered fragments of Madrepores, and nodules of rock 

 apparently foreign to the deposit: these conditions vary and change every 

 few yards, as likewise does the mineral character of the beds ; — the results, 

 in fact, of littoral actien; of a shallow sea where the shells were subjected 

 to strong currents producing hasty deposits and frequent trituration. The 

 Oolitic structure is rather scanty and very uncertain. As a complete con- 

 trast to these conditions, the Great Oolite in the vicinity of Bath may be 

 cited. The rock is there thick-bedded ; the Oolitic structure prevails ; the 

 shells are few, and those chiefly Terebratulce ; the denizens, it may be 

 presumed, of a deep and tranquil sea, in which corals and sponges multiplied 

 and attained large dimensions. In Mr. Lonsdale's list of 31 species of 

 Mollusca from the Bradford clay, Bath Oolite and Fullers earth of that 

 neighbourhood, no less than eight are Terebratulce, and a Crania has since 

 been added ; a larger number of Brachiopods than will be found in the 327 

 Minchinhampton species which I have tabulated. 



The list given by Mr. Buckman, in his " Geology of Cheltenham," from 

 the Bradford clay and Stonesfield slate of the Cotteswolds in the north-eastern 

 part of this county, comprises 5 Radiaria, 2 Terebratulae, 44 Bivalves, 6 

 Cephalopoda, and 19 Univalves Stonesfield has yielded a rich store of 

 remains of reptiles, fishes, Crustacea and land plants, but the Conchologi- 

 cal list is but meagre, and we are nearly destitute of information with regard 

 to the shells of the Great Oolite in its long course through the counties of 

 Northampton and Lincoln. Yorkshire, on the other hand, has found able 

 illustrators in Phillips, Williamson and Bean, the latter gentleman having 

 given, in the M Magazine of Natural History for 1839," a list of fossilsfrom 

 the stratum called Cornbrash in that county, consisting of 4 Radiaria, 3 

 Annulata, 91 Bivalves, 16 Univalves, and 3 Cephalopoda. Unfortunately, 

 however, the rocks beneath the Oxford clay in that county form a great 

 carboniferous series of deposits accumulated in an estuary, and will not allow 

 of its subdivisions being identified with those of the middle and west of 

 England. From this cause the shells have little more than a local value, 

 since we cannot be sure that any particular stratum is contemporaneous with 

 another in a different locality. On looking at these lists, together with those 

 relating to the Oolitic rocks of France, Germany, and Switzerland, we are 

 struck with the great paucity of univalves as compared with the small 

 district of Minchinhampton. 



A careful scrutiny however of various foreign works which bear upon 

 the subject, — of the works of Goldfuss, Roemer, Dunker, Deslongchamps, 

 d' Archiac, &c. — has convinced me, that if any peculiarity exists with regard 

 to the Minchinhampton fossils it is at least of a very limited nature, 

 inasmuch as nearly one-half the entire numbers of bivalves can be identified 



