VOL. XVII. (I) INFERIOR OOLITE— SOUTH COTTESWOLDS 81 



II. Subdivisions recognizable in the Inferior Oolite 

 OF THE South Cotteswolds, and the probable 



CAUSES that governed THEIR DISTRIBUTION. 



The subdivisions recognizable in the Inferior OoUte of the 

 South Cotteswolds are shown in Plate XXI. (end of paper). 

 Therefrom it will be observed that the series has been divided 

 into two main parts, the Freestone and Ragstone Divisions, 

 which are very different lithically, the former consisting mainly 

 of massive freestones, and the latter principally of rubbly rag- 

 stones. The Ragstone Beds have been further separated into 

 "Intervening Beds" and " Top-Beds "—the latter being 

 uppermost. The Top-Beds have the most extensive geograph- 

 ical distribution in the South Cotteswolds ; the Intervening- 

 Beds the least ; while the Freestone Beds occupy an intermediate 

 position as regards geographical extent. 



(xxvii.) Aalensis-Bed (hemera aalensis). — In the South- 

 Cotteswold sections it is not always easy to separate the 

 Aalensis- from the Moom-Bed as regards lithic structure, and 

 ammonites indicative of the former hemera have usually been 

 labelled simply " Moorei-Bed." When separated on the 

 palaeontological evidence, the Aalensis-Bed is found to be 

 extremely thin, and best seen at Coaley Peak and Wotton- 

 iinder-Edge. On the Dorset coast the equivalent beds are 

 much thicker and more readily discernible (see S. S. Buckman, 

 Quart. Journ. Geol. Soc, vol. Ixvi., 1910, p. 64). 



(xxvi.) Opaliniforme-Bed {opaliniformis). — This stratum 

 forms the hard cap to the Cephalopod-Bed. As regards lithic 

 structure, it is easily separable from the beds helow by its 

 non-" marly," but pale-yellow arenaceous-limestone character, 

 and by being usually speckled with angular irony grains 

 instead of smooth oval limonite-granules ; and from the beds 

 above by its more metallic ring when struck with a hammer, 

 and its more compact but less arenaceous character. The bed 

 certainly extends as far south as the neighbourhood of 

 Sodbury, but it is best exposed at Frocester Hill, in Coaley 

 Wood, at Cam-Long Down, Wotton Hill, and Nibley Knoll. It 

 is important to notice that at the base of the Opaliniforme-Bed, 

 and joined on to it, there is often present a rubbly deposit, of 



