SPHiERA. 157 



■ Geniis — CoRHif'ELLA, J. Morn's 'iinl J. Li/rrtf, 185:"!. 

 ('Moll. Great Ool.,' pt. ii, p. 04) 



COEBICELLA 0LAXI3IENSIS, sp. iiov. Plate XXIV, figs. 20 — 28. 



Descri2}tion. —8he\l oval, regularly convex, sligLtly inequilateral, anterior part 

 ratlier larger than the posterior part, length equal to nearly 1^ times the height. 

 Anterior margin rounded. Ventral margin convex, curving rapidly to join the pos- 

 terior margin which fatms an angle with the nearly straight postero-dorsal margin. 

 Umbones broad, inconspicuous, scarcely curved, close together. Surface of shell 

 smooth except for growth-lines. 



Measurements : 



(1) (2) (3) (I) 



Length . 38 . 37 . 30 . 27 mm. 

 Height . 26 . 25 . 21 . 19 „ 

 (1 — 4) Claxby Ironstone, Bcnniworth Haven. 

 Remarlcs. — The genus Corbicella does not appear to have been recognised in 

 deposits of Cretaceous age, but since it is present in tlic Portlandian its occurrence 

 in the lower part of the Speeton Series of Lincolnshire causes no surprise. 



0. claMensis is similar in outline to some forms of G. Pcllati, dc Loriol,' from 

 the Portlandian. 



Type. — In the Sedgwick Museum, Cambridge. 



Disfrihufion. — Spilsby Sandstone (zone of Belomnites lateralis) of Claxby and 

 Donnington. Claxby Ironstone (zone of B. lateralis) of Benniwoith Haven. 



Genus— iivuA:T..\, J. Hoircrhi/, 1822. 

 ('Min. Conch.,' vol. iv, p. 41.) 



SrajiiiA coiiiirGATA, Scm-crh;/, 1822. Plate XXIV, fig. 24; Plate XXV, figs. 1,2; 



text-fig. 2(3. 



1822. Sm^TiKA CORRTJGATA, J. Sowcrhy. Min. Concli., vol. iv, p. 42. pi. cccxxxv. 

 1842. Venus cordiformis, A. Lcyweric. Mrm. Soc. gcol. dc Fi-ancc, ser. 2. vol. 



v, p. .5, pi. v, fig. 8. 



' De Loriol and Pellat, ' Jui-ass. de Boulognc-sur-mer ' (1875), p. 67, pi. xiv. fig. 12. 



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