BIVALVIA. 73 



There is a single specimen only of tins species in Mr. Edwards's cabinet, and this 

 unfortunately is not in very perfect condition, but the figure is faithful, though a little 

 improved. Our shell strongly resembles the figure and description of the French fossil 

 above referred to, and I think it may be safely considered as belonging to that species, 

 A recent species has this name, but it is quite distinct. M. Deshayes says the fossil is 

 entitled to priority. 



18. Modiola tenui striata, Melleville. Tab. XIII, fig. 3. 



Modiola. tenuistuiata. Mellev. Me m. sur les Sab. Tert. Inf. du Cass, de Par. (Ann. des 



Sc. Geol., 1843), p. 39, pi. 2, figs. 17— 19 ; and pi. 3, figs. 

 9, 10. 



Spec. Char. M. testa ovato-ellipticd, tumidd, tenui, fragili, utroque pariter rotun- 

 datd, pedi-regione parvd ; superfcie omnino striata, striis tenuissimis, radiantibus ; 

 striis incrementi elevalis, decussatis. 



Shell ovately elliptical, tumid or deep, thin, and fragile, equally rounded at both 

 extremities ; exterior wholly covered with striae ; radiating lines fine and thin, decussated 

 by elevated lines of growth. 



Length, |ths of an inch. 



Locality. Barton {Edwards). 



This elegant shell is very rare as a British fossil, and of extreme tenuity. M. Melle- 

 ville gives two figures of his species, presenting considerable diversity of character. The 

 British fossil corresponds more closely with his figures 9 and 10, pi. iii, both in the 

 outline and ornament. Our shell has the umbo almost at the extremity, and very slightly 

 projecting. The fine, radiating striae are regularly cut by lines of growth, making the shell 

 appear as if punctured or cancellated. 



19. Modiola? tubicola, S. Wood. Tab. XIII, fig. 12, a, b. 



Spec. Char. M. testa subcglindraced, laevigata, tenui, valde inaquilaterali ; margin ib/cv 

 dorsati et ventrali subparallelis ; pedi-regione parvd, rotundatd ; siphoni-regione compresm. 



Shell subcylindrical, smooth and thin ; dorsal and ventral margin nearly parallel ; very 

 inequilateral ; pedal region small and rounded ; siphonal region compressed. 



Length, fths of an inch ; height, |th. 



Locality. Whetstone ? 



In the museum in Jermyn Street is a specimen of the matrix of London Clay with 

 several tubes of the Teredo, and located with them are two or three individuals of a 

 Modiola ?; these latter have apparently taken their abode in the hollow of the tubes. The 



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