Dr. FiTTON on the Strata below the Chalk. 231 



Monodonta. New. Lowest beds of the Portland stone. Near Blacknore, Isle of 



Portland. 

 Pectenlamellosus. Lowest beds of the stone. Same situation. 

 Plicatiilal Casts of the interior, numerous in the "Roche" immediately over the 



"White bed". Portland. 

 Terebra Portlandica. PI. XXIII. f 6. Very numerous in the " Roche " : also in 



the " White bed ". Portland. 

 Trigonia incurva. PI. XXII. f 14. (Miss Benett * : PI. XVIII. fig. 2.) In the 



"White bed". Portland. 



T gibbosa. Frequent in the " Roche". Portland, and elsewhere on the coast. 



T . A variety, approaching to incurva, but less oblique. Portland. 



Venus parva. (See C2/therea.) 



[^Portland Sand.^ 



Ammonites giganteus. Cross-roads above Kimmeridge Farm, on the north-east. 

 Isle of Purbeck. 



A . New species. In concretions of splintery indurated marl, or soft lime- 

 stone. Lowest beds of the Portland sand. Emmet's Hill : Isle of Purbeck. 



Cucullcea. (A small species.) Portland. 



Exogyra nana. West side of Portland Island, on an Ostrea. 



Ostrea Icevigata. East side of Portland. 



Panopcea depressa. (Mya depressa, Min. Con.) In concretions of dark bluish grey 

 indurated marl. Lower part of the sand. Emmet's Hill : Isle of Purbeck. 



Pecten. A new species ? Upper part of the sands. Blacknore, Portland. 



Serpw/fl tricristata. PI. XXIII. f 8. East side of Portland, ^e/oe. in Kimmeridge 

 clay ? 



S variabilis. PI. XXIII. f. 7. East side of Portland. Qua3. in Kimmeridge 



clay ? 



Trigonia clavellataf. Cross-roads above Kimmeridge Farm on the north-east. Isle 

 of Purbeck. 



Fishes. Scales of fishes are found in strata apparently belonging to this formation, 

 under Gad Cliff, in the Isle of Purbeck. 



Rays of dorsal fins (see the abstract of a paper by M. Agassiz, Pro- 

 ceedings of the Geological Society, vol. ii. p. 101.) occur in nodules either of 

 this formation or of the Kimmeridge clay, on the east coast of Portland. 



[Kimmeridge Clay.'] 

 Ammonites biplex. Numerous in the bituminous shale of Kimmeridge Bay, with 

 transparent sulphate of baryta : sometimes along with an Ostrea. 



* *' A Catalogue of the Organic Remains of the County of Wilts;" 4to, with 18 plates. 

 Warminster, 1831. 



t Besides the shells mentioned above, two or three other bivalves, of which the genera are 

 indistinct, have been found in the Portland sand, at Emmet's Hill and other places, in the Isle of 

 Purbeck. 



VOL. IV. SECOND SERIES. 2 H 



