602 ME. C. B. WEDD O'N THE [NoV. 1 898, 



' Coral Rag ' can be found coming on at the top at about 50 yards 

 from the southern end. There are some indications of a passage 

 from the oolitic to the Eag-tj^pe. A slight dip brings the Rag 

 graduaUy down the bank-side to the north until, at about 25 yards 

 from the northern end, the dip increases and the base of the Rag, 

 here seen as a hard crystalline band with oolite below, comes down 

 almost to the floor of the quarry at the northern end. The upper 

 part of the bank at the northern end is grass-covered, but the lower 

 part shows a good exposure of Rag almost to the bottom. 



The limestone is here hard and somewhat cr}'stalline, there being 

 several very hard crystalline layers in which the coral-structure is 

 sometimes almost obliterated. Still, an examination of the exposure 

 in the northern bank shows coral continuously from top to bottom, 

 only interrupted by thin marlj- partings, probably due to solution 

 and filtration along divisional planes. Owing to the hardness of the 

 rock, to the mode of preservation and to rapid alteration of the coral 

 on the surface, it is difficult to determine whether Isastraa or 

 Thamnastrcea predominates, but the two certainly form what might 

 be called the framework of the rock. At the base is a well- 

 marked layer of Isastrcea explanata, continuous for some few yards 

 as far as it could be traced. Many large slabs of Thamnastrcea 

 arachnoides and Th. concinna are seen in a heap of material quarried 

 here. 



It has been stated that the Rag here contains some oolitic 

 grains. I have frequenth' looked for them, but never found any 

 in the true Rag, except at its junction with the lower beds. 

 The Rag-limestone is particularly pure, but no doubt varies slightly 

 in composition with the different degrees of crystallization of 

 individual layers. Typical specimens, not taken from the massive 

 crystalline bands, when dissolved in hydrochloric acid, showed 

 sometimes scarcely any residue, and yielded carbonate equivalent to 

 as much as 98 per cent, of carbonate of lime. 



It is often assumed that the fauna of the oolite of the Southern 

 Quarry is much the same as that of the Northern Quarry. This, 

 however, is not the case. The lowest beds of the Southern Quarrj'-, 

 exposed at its southern end, are not ver}' fossiliferous. I have 

 examined carefully the exposure of these beds and a heap of material 

 quarried there, and obtained : — 

 * Ammonites (Cardioceras) vertebralis, \ * Ostrea {Alectryonia) gregaria, Sow. 



var. cawtonensis, Bl. & H. 

 * Cerithium muricatum, Sow. 

 Littorina muricata. Sow. 



* Area sp. 

 Exogyra nana, Sow. 

 Gervillia sp. 



* Horaoraya tremula, Buv, 

 Isocardia sp. 



* lAfhodomus inclusus, Phil. 



* Mytilus pectinatus, Sow, 

 Mytilus sp. 

 Opis Pkillipsif Mor. * Montlivaltia dispar, Phil 



Fecten Jihrosus, Sow. 

 * Queiistedtia Icevigata, Phil. 



Vermilia sulcata, Sow. 



* Cidaris fiorigem,ma, Phil, (spines). 

 Echinobrissus scutatus, Lam. 

 Holectypus depressus, Leske. 

 Fygaster umhrella, Ag. 



* Pentacrinus sp. 



* Montlivaltia dis^ 

 Opis sp. . * Ehabdophyllia Phillipsi, E. & H. 



