LOWER MAS: DUMBLETON. 
not plentiful. I obtained Ammonites Jamesoni, Belcmnitcs, Gry- 
phcRa cymbium, G. arcuata, and Hippopodium ponderosum. 
Near Didcot Farm, north of Dumbleton Hill, a brickyard 
showed blue, and brown marly clays, with many hard reddish 
ironstone-nodules and grey cement-nodules, layers of shelly lime- 
stone and thin shnly limestone. Among the fossils obtained were 
Ammonites striatus, A. cnpricornus, Inoceramus ventricosus, 
Modiola scalprum, Pecten, Pholadomya ambigua, Plcuromya 
costata, and Unicardium cardioides* The beds represent the 
highest stage of the Lower Lias (zone of Am. capricornus). 
* See aUo Wright, Proc. Cotteswold Club, vol. iii. p. 153. 
