oouri: ov the cottkhwold hills. 557 



from this bed t^liows iliat the limestone luis a struciuro different 

 from that observed in tlic freestone below the typical Pea (irit at 

 Strond. Some of the fra^j^ments arc seen to be thickly coated with 

 the tubules of O'irvdnella 2>'solitiC(( in a good state of preservation, 

 Avhile other fragments arc free from it. Among the fragments portions 

 of cchinodermata (especially the ossicles of crinoidS), shells, and 

 foraminifera were noticed. AVith n^gard to those coated with 

 the tubules of Glrvauella pisolitlca, this observation corresponds 

 with what I have found in the upper portion of the same series in 

 No. 3 raihvaj'-cuttiiig east of Andoversford. 



Beds Nos. 5 and 1 1 are similar to No. 4. 



Bed No. 12. This bed shows no sign of Glrvauella pisolitica and 

 is a true crystalline oolite. The granules show the radial structure, 

 iind in some the concentric is apparent ; in others there is only the 

 dark granular structure. The spaces between the granules ara 

 tilled in with clear calcite. 



Bed No. 15 is one of the typical Pea-Grit Series, and is made up 

 of the large pisolites which stand out in weathered specimens. 

 Thin sections show that the spherules are those of Gii^anella 

 pisolitica. 



Bed No. 17 is 7=1 feet thick, and, with the exception of the upper- 

 most 8 inches, contains no pisolites. A thin section of the lime- 

 stone from about the centre proves it to be made up of crystalline 

 oolitic granules, in some of which a faint tubular structure could 

 be distinguished. A thin section of the rock taken from the 

 uppermost 8 inches shows that some of the organic fragments are 

 enclosed by the tubules of Girvanella pisolitica ; the fragments 

 thus coated constitute the small pisolites. 



Bed No. 19 is another bed of typical Pea Grit. 



Bed No. 20 is 3 feet thick and full of oolite granules of the 

 ordinary type. Mounted in Canada balsam these show the usual 

 concentric structure, with streaks of calcite and a dark granular 

 appearance. This oolite is one of the few which I have been enabled 

 to polish, and in thin sections so prepared the concentric arrangement 

 noticed in the ordinary preparations is much less apparent (PI. XX. 

 iig. 3). The object shows a dark granular crust around the nucleus, 

 which is studded with spots and streaks of calcite. 



Above this bed no pisolites appear, and the strata assume a free- 

 stone character. The line between the Pea-Grit Series and the Lower 

 Freestones, which follow, might be drawn at Bed No. 21, but it is 

 more convenient to do so at a few feet above, at what Mr. S. S. 

 Buckman and myself have called the " Polyzoa Bed."' It is charac- 

 terized by the number of polyzoa which it contains, and may perhaps 

 be represented in the Southern Cotteswold area by the well-known 

 (Joral Bed which occurs at that horizon. 



(d) The Buildinfj Freestones. 



The middle division of the Inferior Oohte in the Cotteswold area 

 consists of freestones, which are di\ided by the so-called Oolite Marl 

 into the Lower and Upper. 



