286 Reports and Proceedings — Oeological Society of London. 



Upper Keuper is well displayed, whilst there is a sharp line of 

 demarcation hetween the former and the Avicula-contorta Shales. 

 Most of the characteristic fossils of the British Ehsetic are met with 

 at Pylle Hill, together with a few forms which are new to England, 

 and some of these possibly new to science. 



A detailed section of tlae subdivisions of the Ehsetic and adjacent 

 beds, and a list of Eheetic fossils found in the section, are given by 

 the author. 



2. "A Microscopic Study of the Inferior Oolite of the Cotteswold 

 Hills, including the Eesidues insoluble in Hydrochloric Acid." By 

 Edward Wethered, Esq., F.G.S., F.C.S., F.E.M.S. 



The ai;thor gives the following main divisions of the Inferior 

 Oolite of the Cotteswold Hills in descending order : 



Eagstones. 



Upper Freestones. 



Oolitic Marl. 



Lower Freestones. 



Pea Grit. 



Transition beds resting on Upper Lias. 



The strata are described, and the results of microscopic examination 

 of the different beds given. These latter confirm the author's 

 views as to the important part which GirvanellcB have taken in the 

 formation of oolitic granules ; whilst an examination of the borings 

 referred to by Prof. Judd in the discussion of Mr. Strahan's paper 

 " On a Phosphatic Chalk " convinces the author that these have no 

 connexion with the genus Girvanella. 



In the second part of the paper the insoluble residues left after 

 treating the various deposits with acid are considered. They contain 

 chiefly detrital quartz, felspars, zircons, tourmaline, chips of garnet, 

 and occasionally rutile. In the argillaceous beds silicate of alumina 

 was found to occur plentifully. The detrital material is considered 

 to be due to denudation of crystalline felspathic rocks, and not of 

 stratified ones. This view seems to be supported by the quantity 

 of felspar and its good state of preservation. 



The paper concludes with a consideration of the quantity of 

 residue and the size of the quartz-grains in the different deposits, 

 which are summarized in the following table : — 



Percentage auartl^o.?ains 



of Residue. '^'^rmiriir ' 



Eagstones 2-8 -17 



Upper Freestones 1-1 -12 



Oolitic Marl 3-2 -09 



Lower Freestones 1'8 '13 



Pea-Grit Series 5-0 -14 



Transition Beds 38-3 -13 



This shows a great falling off in the percentage of residue above 

 the Transition Beds. That of the Freestones is remarkably low, 

 and it would appear that these rocks were formed under conditions 

 which allowed of very little sediment being deposited. 



EEEATUM. — In the Maj' Number, p. 240, last line but one of first paragraph, 

 for " Metamorphic " read "Metatropic." 



