1857] BUCKMAN OOLITES. 115 



vided for the maintenance of the balance of the testaceous animals 

 during the deposition of the Great Oolite of England. The great 

 mass of the Testacea are bivalves, and in species they exceed, by 

 about one-fourth, the united number of the Gasteropoda, Cepha- 

 lopoda, and Echinodermata*." 



Hence then the fossils of the Great Oolite, taken as a whole, more 

 nearly conform to that which pertains to the shelly freestone and 

 building-stone of the Inferior Oolite ; and, as before remarked, it is 

 curious to find how many shells are common to the two ; however, 

 in as far as hand- specimens of these two building- rocks are con- 

 cerned, we can usually find some distinctive fossils, the more com- 

 mon of which will be found in most of the species of Tancredia of 

 Lycett, Pecten vagans, Lima cardiiformis, L. duplicata, and Natica, 

 Purpura, Alaria, Melania, and others of the univalve class, so many 

 of which are not only distinctive, but of common occurrence. 



The Brachiopoda, which are so abundant in the rag beds of the 

 Inferior Oolite, are few in species in the Great Oolite, and usually 

 only occur in the occasional marly partings ; the bed, however, 

 marked 5 is tolerably persistent over a wide area, and at Bibury 

 contains whole masses of the T. maxillata, of a peculiarly large and, 

 for the most part, old and rugose form. The same shell occurs abun- 

 dantly at Foss Bridge on the Cirencester and Northleach road, but 

 here only in the young state — a circumstance which might lead to 

 the consideration of it as a distinct species ; whilst at Northleach the 

 same band of marl contains this small form, together with occasional 

 examples of a Terebratula, referred by Mr. Hullf to T. digona, but 

 differing in being broader, thicker, and not so square at the base. This 

 form, however, I take to be the representative, if not derivative of 



Terebratula indentata, Sow. Lias. Terebratula obovata, Sow. (with its 



cornuta, Sow. Lias-marlstone. allies). Cornbrash. 



emarginata, Sow. Inf. Oolite. ornithocephala, Sow. Oxford 



digona, Sow. Bradford Clay. Clay. 



I know this view will be dissented from by naturalists in general ; 

 still I cannot help thinking that, when collectors compare all the 

 forms they can get without looking after merely typical specimens 

 (which by the way are often exceptions), their tendency, like mine, 

 will be in this direction. 



Among the higher animals, Fishes may be referred to as presenting 

 an important characteristic of the Freestone of the Great Oolite, when 

 compared with the Inferior Oolite. In the latter, fish-remains are very 

 uncommon ; but in the former, teeth of various genera of the follow- 

 ing families may be found in almost every quarry : — 



Pycnodonts. — Vomerine bones, with whole rows of teeth, not un- 

 common ; single teeth dot the stones very commonly. 



Cestracionts. — Large quadrangular teeth of Strophodus are com- 

 mon throughout the Great Oolite, with others. 



Hybodonts. — Separate teeth of various species, with the rest. 



* ' Monograph of the Mollusca from the Great Oolite,' Morris & Lycett, p. 5. 

 t Memoirs of Geological Survey, Geology of Country around Cheltenham, bv 

 E. Hull, Esq., p. 62. 



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