I 



OOLITE OF THE COTTESWOLD HILLS. ;)•).» 



and more oolitic in the Stroud area, but the Lcckharapton-llili 

 section, as being the first described, sliould be regarded as normal 

 for the Cotteswold area. In this paper I shall revert to the term 

 "■ Pea-(jrrit Series,'' making it include the limestones which follow 

 the Transition Beds and range up to the Lower Freestones. I shall 

 justify this course as I proceed. 



The lower beds of the Pea-Grit Series are exposed in Xo. 3 cutting 

 on the Midland and South-Western Junction Railway east of An- 

 dovorsford, where they rest on the " Transition Eeds." They consist 

 of coarse yellow limestone with occasional argillaceous bands, and 

 may be taken at not less than 20 feet, but the exact thickness is 

 doubtful on account of one or two small faults. Thin sections of 

 these limestones show that they are made up of fragmentary organic 

 remains, chiefly those of echinodermata, among which the ossicles 

 of crinoids are the best preserved (PI. XX. fig. 1); foraminifera, 

 polyzoa, and the valves of ostracoda are also found in them. 



Proceeding higher in the series we notice that the beds become 

 thicker and contain large oolitic granules. Examined in thin sections 

 under a microscope, the limestones are seen to be of much the same 

 structure as those to which reference has just been made at the base of 

 the series, but there is one important difference : it is that many of 

 the organic fragments are surrounded with a crust (PI. XX. fig. 2), 

 and this crust is found to consist of the tubules of Girvanella piso- 

 litica. Fragments so surrounded are the oolitic granules noticed in 

 the rock. The beds continue to become more oolitic and the o-ranules 

 increase in size, but what I term the typical Pea Grit does not occur 

 in Xo. 3 cutting above mentioned. Some of the beds, however, 

 .contain small pisolites. 



With the above series are one or two argillaceous beds, and to one 

 of these I desire to call special attention. It is characterized by 

 the presence of calcareous sponges and polyzoa, and it is so well 

 defined by these fossils that I feel justified in naming it the Sponge 

 Bed. It is 1| foot thick, and besides the sponges and polyzoa 

 contains numerous belemnites and shell-fragments, the latter for 

 the most part badly preserved. The sponges have been submitted 

 to Dr. G. J. Hinde, F.G.S., who has kindly determined them as 

 follows : — Lymnorea raamillosa, Lam., Lymnorea ramosa, Hinde, and 

 Peronella tenuis, Hinde. 



The locality known as the Horsepools is on the crest of the 

 Cotteswold Hills, between Gloucester and Stroud. The actual 

 junction with the sands is not exposed, owing to the fact that the 

 Transition Beds are useless for commercial purposes and consequently 

 are not opened out. Mr, W. C. Lucy, F.G.S., kindly accompanied 

 me to a (piarry in which strata typical of the district were exposed. 

 They consist of yellow limestones which are the equivalents of the 

 Pea-Grit series in No. 3 cutting already alluded to. 



