302 Dr. FiTTON on the Strata below the Chalk. 



Serpula. Shotover, with Ostrea ; Brill ; Coney Hill; Dunton, in green matter. 



Trigonia clavellata. Long Crendon ; Casts in conglomerate, with siliceous pebbles ; 

 and in sandy limestone, with numerous green particles. Dunton, Bucks; with 

 Mytilus. 



T gibbosa. Denton, Oxf. Hartwell, Bucks; with Cardium, in bluish grey 



stone. Dunton, and Whitchurch, Bucks. 



T gibbosa : a variety, less oblique. Brill. 



T incurva. Brill, Bucks. 



Venus. Shotover Hill, Oxf.; with Perna quadrata. Hartwell, Bucks; with Tri- 

 gonia, in soft stone. 



[Kimmeridge Clay.'\ 



Ammonites biplex. Clay-pits near Aylesbury. Road from Aylesbury to Whitchurch. 



A • biplex (small). East Claydon, Bucks ; 20 feet from surface, in clay: 



A giganteus ?. Clay pits south-west of Stewkiey, Bucks : in blue clay. 



A Gulielmi. East Claydon, Bucks: in clay ; beautifully iridescent. 



A like Gulielmi. Quainton, Bucks. 



A— Selliguimis. ClophiJl, Bedf. Mr. Goodhall. 



A (probably new). Clay-pits, south-west of Stewkiey, Bucks, in blue clay. 



Aptijchus (Von Meyer). PI. XXHI. fig. 11. Roadside between Aylesbury and 

 Whitchurch, about a furlong from Hardwick. Clay pits south-west of Stewk- 

 iey ; fragments of very large specimen. 



A (a smaller species ?). Roadside between Aylesbury and Whitchurch. 



FiXogyra nana. Between Aylesbury and Whitchurch : with Ostrea Icevigata. 



E virgtda. PI. XXHI. f. 10. (Gry;j/(«^a ti/rg-M/a of Deshayes.) Roadside be- 

 tween Aylesbury and Whitchurch. Clay-pits south-west of Stewkiey : good 

 specimens in bluish grey clay. 



GryphcBa bullata. Clophill, Bedf., Mr. Goodhall. 



G dilatata. Wolvercot, Bucks ?. Clophill, Bedf. 



G xirgida. See Exogyra. 



Mytilus. Quainton. 



Ostrea deltoidea. Aylesbury Clay-pits : a distorted form of the shell. Little Brick- 

 hill, clay immediately below surface : line specimens. 



O laevigata. Between Aylesbury and Whitchurch. 



O (young). Thornborough, Oxf. 



O lacviuscula (young). Road from Aylesbury to Whitchurch : in blue clay. Little 



Brick Hill, Bedf. 



O near to delloidcea, but wider at the hinge; still very thick. " In a bed of stiff 



" clay, about two miles north-north-west of Leighton, under the red sand of the 

 " heath, and about 20 feet above the river." Mr. W. Mathews of Leiohton : 

 Roadside between Aylesbury and Whitchurch ; Bucks. 



Panopaa depressa. Headington Quarry, Oxf. 



Pecten arcuatus. Vicinity of Aylesbury. 



P Lens. Little Brickhiil. Brow of the hill, in clay immediately below sand. 



