34 EOCENE MOLLUSCA. 



23. Ostrea zonulata, S. Wood. Tab. X, fig. 4, a — c. 



Spec. Char. 0. testa elongato-ovatd, tenui, fragili, valvd sinistra convexd, profunda, 

 iuibricatd ; imbricibus tenuibus, distantibus j valvd dextrd plana, lamellatd ; cicatriculd 

 musculari minima, reniformi ; area cardinali angustd. 



Shell elongately ovate, thin, and fragile ; left or lower valve convex, deep ; upper valve 

 flat and lamellated, lamellae or fimbriations thin and distant ; muscular impression small ; 

 cardinal area narrow. 



Longest diameter, 1 \ inch. 



Locality. Hill Head, near Stubbington. {Fisher.) 



The above shell has been recently obtained by the Rev. Osmond Fisher, who has kindly 

 permitted me to have it figured. 



It somewhat resembles 0. velata in the regularity of the imbrications, but it differs in 

 having these imbrications fewer in number, and they are broader, more thin, and delicate ; 

 besides which, the upper valve in this species is quite free from the striae which form 

 so marked a feature in the upper valve of 0. velata. 



Fig. 4, Tab. VIII, represents a specimen of the upper valve of an oyster, from the 

 cabinet of Mr. Edwards, and found at Bracklesham. This was figured previous to the 

 discovery of the above species, and it was then considered so closely to resemble the French 

 Eocene fossil, 0. lamellaris, Desh. (Coq. foss. des Env. de Paris, pi. 54, figs. 3, 4), as to 

 deserve a representation, from a possible identity ; but in the subsequent work by the same 

 author (An. sans Vert, du Bassin de Paris, t. xi, p. 106), that shell is referred to 0. 

 mtdtistriata, in which species the upper valve is represented as finely and closely striated. 

 Our shell is quite free from striae of any kind, and it does not appear to have been decor- 

 ticated. I am now therefore inclined to refer it to the present species. 



In the ' Quarterly Journ. of the Geol. Soc.,' 1854, p. 117, Mr. Prestwich speaks of an 

 oyster as having been met with at Kyson (0. Bellovacina ?); but the specimen cannot be 

 found. Mr. J. C. Moore obtained an oyster in an estuary deposit in the New Forest. 

 'Journ. Geol. Soc./ vol. v, p. 316, 1849. This specimen also we have not been fortunate 

 enough to find. 



