THE COKALLIAN EOCKS OF ENGLAND. 281 



seen, their identity might be considered doubtful ; but their aspect 

 and the stratigraphical connexion with the last-described quarries 

 leave no doubt on the subject, especially as they are overlain close 

 by by similar flaggy oolites, which contain Trigonia Meriani. 



In spite, therefore, of their very local nature and their compara- 

 tive paucity of fauna, these false-bedded limestones are of great im- 

 portance economically, and play the same part here that the Coralline 

 Oolite does in Yorkshire, with which they may possibly agree in 

 age, though more probably they are a little older. We may com- 

 pare them also in time perhaps with the Osmington Oolites. 



The next set of beds in the ascending order at Sturminster is a 

 very curious one. As it planes off the edges of the beds below and 

 lies on their uneven surface, we may conclude that some time elapsed 

 between the deposition of the two. The rubbly character of these 

 rocks and the abundance of Cidaris florigemma and of other 

 fossils would lead us to consider these beds the equivalent of the 

 Coral Rag of other districts, and, indeed, to have been deposited at 

 the same time that the coral reefs were in growth further to the 

 west and north, and to have been derived from them, although it 

 must be acknowledged that the list of fossils includes some which 

 are usually only found in older deposits than the Coral Rag proper. 



We are not able to trace this division in its typical form to any 

 distance. In the section at Todbere above described it is doubtless 

 represented by the massive limestone No. 3, though Cidaris flori- 

 gemma has not been found in it ; but it must be of an extremely 

 patchy character, as, even at Marnhull it cannot be recognized, and 

 Cidaris florigemma is not to be found in the quarries at present 

 exposed to the south of Sturminster, or, indeed, elsewhere in this 

 district. 



There are not usually any limestones overlying the " Coral Rag ;" 

 and if the rubbly limestones of Sturminster represent this, then the 

 succeeding upper calcareous series are a rather exceptional develop- 

 ment. In the Marnhull quarries the upper beds, in the form of flaggy 

 oolites, as represented in figure 3, overlying the false-bedded series, 

 undoutedly represent them ; but beyond this neighbourhood the 

 type is too much altered to enable us to trace them. 



It has been seen that we have been unable to identify the beds 

 above the pisolites at any distance from Sturminster; but if the 

 false-bedded series and the rubbly and upper limestones are so local, 

 what has taken their place ? 



With regard to the district south of Sturminster, the few open- 

 ings all expose limestones whose approximate age can only be 

 determined by their fossils. At Mappowder is a quarry in rubbly 

 shell-limestone, in which the fossils consist of abundance of Trigo nia 

 clavellata, also Chemnitzia heddingtonensis, Modiola varians, Lucina 

 aliena, and, most astonishing, Rhynclionella Thurmanni, a fossil un- 

 known elsewhere at so high a horizon. A more fossiliferous quarry 

 may be seen at Glanvilles Wootton, composed of hard blue finely 

 oolitic ragstone, containing shell-layers, and graduating into pure 

 shell-limestone. The fossils here are Trigonia clavellata (abundant), 



