2] I CRETACEOUS LAMELLIBRANCHIA. 



Type. — Internal casts from the Hythe Beds of Pulborough, in the British 

 Museum. 



Distribution. — Lower Greensand : Crackers of Atherfield. Recorded by Fitton 

 from the Perna-bed, Atherfield Clay, and Beds VI — IX, XIII, XIV near Atherfield. 

 Ferruginous Sands of Shanklin. Atherfield Beds of Peasmarsh, East Shalford 

 and Sevenoaks. Hythe Beds of Pulborough. Folkestone Beds of Folkestone. 



Corbula gaultina, Pictet and Campiclie, 1864. Plate XXXIV, figs. 14 — 16. 



1864. Corbula gaultina, F. J. Pictet and G. Campiche. Foss. Terr. Cret. Ste. 



Croix (Mater. Pal. Suisse, ser. 4), 

 p. 34, pi. c, figs. 3, 4. 



1870. F. Stoliczka. Palseont. Indica, Cret. Fauna S. India, 



vol. iii, p. 40. 



Description. — Shell subtriangular, rounded, inflated, slightly inequivalve, a 

 little longer than high, moderately inequilateral. Anterior margin rounded. 

 Posterior margin subtruncate, oblique. Umbones prominent, rather high, curved 

 forward, with an inconspicuous carina cutting off a concave postero-dorsal area. 

 Ornamentation consists of small, concentric ribs. 



Measurements : 



(i) (2) (3) (4) 



Length . 5*5 . 5*0 . 4*6 . 4*0 mm. 



Height . 5-0 . 4-5 . 4-0 . 3-6 „ 



(1—4) Gault, Folkestone. 



Affinities. — In this species the shell is relatively shorter and more inflated than 

 in G. elegantula, d'Orbigny. 1 



G. gaultina may perhaps be, as was pointed out by Pictet and Campiche, 

 identical with G. social is, d'Orbigny,' 2 of which no sufficient diagnosis has been 

 given. 



Remarks. — Numerous individuals of this species are found close together in 

 groups. "When the surface of the shell is not perfectly preserved the ribs become 

 indistinct. 



Type. — From the Gault of Folkestone. 



Distribution. — Lower Gault (Bed 2) of Folkestone. 



1 'Pal. Fran?. Terr. Cret.,' vol. iii (1846), p. 460, pi. ccclxxxviii, figs. 14—17. 



2 'Prodr. de Pal.,' vol. ii (1850), p. 136. 



