TBLLINA. 1 75 



Sub-genvs — Linearia, T. A. Conrad, 1860. 



(' Journ. Acad. Nat. Sci. Philad.,' ser. 2, vol. iv, p. 279, and ' Amer. Journ. Conch.,' vol. vi 



[1870], p. 73.) 



Tellina (Linearia), sp. Plate XXVII, fig. 9. 



Description. — Shell oval, moderately convex with flattened sides, nearly 

 equilateral. Anterior margin rounded. Ventral margin slightly convex. Posterior 

 margin slightly truncated, rounded. Umbones inconspicuous. Postero-dorsal 

 region slightly compressed, but not limited by a carina. 



Ornamentation consists of numerous, strong, regular, concentric ribs separated 

 by narrow grooves ; and a few small radial ribs on the anterior and posterior 

 parts, those on the latter sometimes not reaching the margin. Length 16*5 mm.; 

 height 10*5 mm. 



Affinities. — This species, of which only a few examples have been seen, is 

 closely allied to, if not identical with, T. Rauliniana (d'Orbigny), 1 but the posterior 

 ribs are less prominent. The shell is less elongate than is d'Orbigny's type, but 

 scarcely differs in this respect from the example figured by Pictet and Campiche. It 

 is more elongate and has the postero-dorsal region less flattened than in 

 T. subeoncentrica (d'Orbigny). 2 T. subhercynica, Maas, is another similar form. 



Distribution. — Lower Greensand (Crackers) of Atherfield. Atherfield Beds of 

 East Shalford. 3 



Tellina (Linearia) subtenuistriata, d'Orbigny, 1850. Plate XXVII, figs. 10 — 13. 



1836. Amphidesma? tenuistriatum, J. do C. Sowcrby. Trans. Geol. Soc, ser. 2, 



vol. iv, pp. 239, 341, 

 pi. xvi, fig. 7. 

 1850. Tellina subtenuistriata, A. d'Orbigny. Prodr. de Pal., vol. ii, p. 159 



(non T.tenuistriata, Deshayes, 

 1824). 

 1854. Amphidesma ? tenuistriatum, J. Morris. Cat. Brit. Foss., ed. 2, p. 183. 



1 For references see p. 176, footnotes 1 and 2. 



2 Some specimens from the Folkestone Beds of Folkestone agree in form with T. subeoncentrica, 

 but owing to the imperfect preservation of the surface the character of the ornamentation cannot be 

 made out satisfactorily. 



3 It is possible that Tellina sequalis, Mantell (nom. nud.), from the Lower Greensand of Parlmm, 

 may be the form described above. Mantell, ' Trans. Geol. Soc.,' ser. 2, vol. iii (1829), p. 211. 



