Dr. FiTTON on the Strata below the Chalk. 177 



Cypris ; impressions only, without traces of the shell : Hollington, near Has- 

 tings. In nodules of clay iron ore : Cliffs west of St. Leonard's. In shale, 

 called " Shab," alternating with beds of limestone called " Greys," (a stone al- 

 most entirely composed of thin shells) : Limestone pits north-west of Battle : F. 

 With Paludinajluviorum, in bluish compact and sparry limestone, (" Sussex mar- 

 ble"); Daniel's Water, Kent. In sand-rock near Tunbridge Wells : M. At the 

 top of the Weald clay, mixed with bivalves of the Lower green-sand; Stopham 

 brick-yard near Pulborough : Martin. 



Cyclas media. (Young.) Plate XXI. f. 9. Hastings sand, Hollington, in hard grit ; 

 shell converted into carbonate of lime : F. Etchinghara near Robertsbridge, 

 Sussex : M. 



C . (A gibbose variety.) Plate XXI. f. 11. Penhurst pits, in a bed of lime- 

 stone, about 3 inches thick called " Top-greys" : F. 



C . A wider species than media. Hastings sand, Hollington : F. 



C membranacea. {Cyrena membranacea, Ann. of Phil. 1824. vni. p. 376.) Cliff west 



of St. Leonard's, in sandy shale, with Cypris : F. Weald clay, Shipley, near 

 East Grinstead, Sussex, with a spiral univalve (Potamides ?) : M. Limestone 

 pits near Battle : F. Penhurst, Ashburnham, and Pounceford : M. 



C subquadrata. Plate XXI. f. 8. Hastings sand. East Cliff, Hastings, in soft, 



fine, sandy clay, not effervescent : also cliff west of St. Leonard's : F. 



C . One or two other species, probably new, occur in the Weald clay, at Ather- 



ley, Surrey : F. 



Cy/jm granulosa. PI. XXI. f. 4. In ferruginous sand, Tilgate Forest : M. 



C tuberculata. PI. XXI. f. 1. Frequently black. With Cypris Valdensis and 



Paludina elongata, in nodules of clay iron ore, near the top of the Weald clay : 

 found by Lord Greenock, at Hythe 



C Valdensis. PI. XXI. f. 1. (C Faba, Ann. of Phil. 1824, viii, p. 376.; Min. 



Con. Tab. 485.) This fossil occurs in such numbers in every part of the Wealden 

 group, that it may be considered as characteristic of the formation ; and being 

 found in all the places where these strata have been hitherto observed, the speci- 

 fication of localities would be superfluous. Its profuse abundance may perhaps be 

 accounted for by the fact, that the animal which inhabits the valves or crusts, sheds 

 them periodically*. The Cypris to which the specific name of" Faba," was given 

 by M. Desmarestf, occurs in strata probably superior to the chalk ; and though 

 the characters of the valves nearly approach to those of the Wealden Cypris, 

 M. Deshayes is of opinion that it probably constitutes another species;}:. On these 

 grounds, I have thought it expedient to adopt a new specific name for the fossil 

 represented in PI. XXI. f. 1.; and that of Valdensis (of, or belonging to the 

 Wealden) is intended to indicate both its geological or stratigraphical position, 

 and the local situation of the tract in which it has hitherto been found in the 



* Lyell " Principles," &c., 3rd edition, vol. iv. p. 98. 



f Brongniart and Desmarest, " Crustacees Fossiles," p. 14.], PI. XL, fig. 8. 

 i " Coquilles Characteristiques," p. 255, PI. 10. figs. 4. and 5. 

 VOL. IV. SECOND SERIES. 2 A 



