172 



E. P. TOMES OlS" aiADEEPOEAEIA 



yielding large blocks, the one belonging to the upper zone, the 

 other to the lower." 



Bed number 20 of my section is the thick-bedded oolite mentioned 

 by Mr. Hull, and constitutes the lower zone, and this, he further on 

 says, is the equivalent of the Stonesfield Slate. All above it (having, 

 however, a much greater thickness than is stated by him) corre- 

 sponds with the upper zone. The oyster which is so abundant in 

 beds 17 and 19, and which occurs also in some of the other beds, 

 is probably Ostrea Soiuerhyi, and its prevalence in these beds, as 

 well as the nature of the stone and shale of which they are com- 

 posed, renders it quite probable that this part of the Milton section 

 corresponds with the oyster-bed in the Stonesfield cutting. If such 

 is the case, and the compact oolite below is identical with the 

 Stonesfield Slate, further evidence in proof of the identity of the 

 Stonesfield and Milton coralliferous deposits is unnecessary. 



There is, however, considerable dissimilarity between these two 

 coral beds ; the one at Milton being much more uniform in texture, 

 as well as much harder than the one at Stonesfield. The former is, 

 indeed, so compact a stone, that it is only by fortunate fractures 

 that the enclosed corals can be examined ; and what adds more to 

 the difficulty of securing satisfactory specimens is their highly 

 crystalline condition. This coralliferous layer does not, indeed, 

 present the usual characteristics of a coral bank, but rather resembles 

 some near deposit into which they have been removed from the 

 place of their growth. 



My previous assertion that some of the corals figured by Professor 

 Duncan, from the collection of the late Mr. Brown of Cirencester, 

 came from Tairforcl, has met with partial corroboration. Two 

 of the species, CJioricastrcea ohtiisa and Cryptoccenia tiiherosa, do not 

 occur in the cparry from which Mr. Brown's collection was made, 

 and are not to be seen in the Collection given by him to the Museum 

 at Oxford. The species were, I do not now entertain the least doubt, 

 originally in Miss Slatter's collection, and had been obtained from 

 Fairford. 



A visit recently paid to Cirencester gave me the opportunity of 

 inspecting the linie-kiln cjuarry, three miles along the Stroud road, 

 and of preparing the following section which appears in it. It was 

 from this quarry that Mr. Brown obtained his specimens. 



ft. in. 



1. Surface-soil .., 1 6 



2. Soil and shattered stone 1 6 



3. A soft friable bed of an earthy nature, of a deep yellow colour, 



and containing rubbly nodular stone. A species of Echino- 



brissus occurs in it 1 6 



4. Hard, fine-grained, whitish stone, non-oolitic, with a somewhat 



conchoidal fracture, and penetrated by tortuous, but more or less 

 vertical and anastomosing perforations, which are filled with 

 the soft earthy part of the'bed above. No fossils observed 2 9 



5. Fine-grained oolite of a light yellowish colour, in some parts 



nearly white. Fossils rare , 3 



6. Coral-bed. Eesembles the last, but is a little coarser. Contains 



a Nerincsa and other univalves, and about 15 or 16 species of 



corals 2 



7. Compact yellow oohte with very few fossils 2 



