86 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [DoC. 6, 



16. Pebna ? Eamsayi, spec. nov. 



Shell oblique, elongated, moderately convex, thin. Surface with 

 rounded wavy concentric folds, which extend across the shell. Ear 

 large, crossed by sigmoid folds or lines. Hinge unknown. Length 

 4 inches ; breadth fths of length. 



Locality and position. — Southerndown series near Sutton. 



My specimen only shows the interior of the shell, which is, how- 

 ever, very thin. The hinge-line also is broken off, so that the genus 

 is uncertain. It bears some slight resemblance to Perna infraliasina 

 Quenst., but it is considerably larger than that shell. Until the ex- 

 ternal shell is known, it cannot be referred to that species. I dedi- 

 cate it, therefore, provisionally, to Prof. A. C. Eamsay, F.R.S., Pro- 

 fessor of Geology at the Eoyal School of Mines. 



17. Plicatitla acuminata, Terq. et Piette. 



I have specimens corresponding to the description given of this 

 shell by Terquem and Piette (Mem. Soc. Geol. de France, 2nd series, 

 vol. viii. p. 107, pi. xiii. figs. 20, 21), the distinguishing character 

 being the acute hinge with transverse folds and radiating ribs. They 

 cite it as a rare shell, in beds containing Belemnites acutus. 



18. Plicatula intussteiata, Emm. 



This is one of the most characteristic species. In England it is 

 a characteristic Rhsetic species ; but on the continent it passes up into 

 the Planorbis-zone, if not higher. The species P. Lothatingice, Terq. 

 et Piette, evidently belongs to Emmerich's type ; it is cited from 

 the Planorbis-zone. Dumortier says (Infralias, p. 76) that it is 

 characteristic of the Planorbis-zone, never being found helow or 

 above ; it is probable, therefore, that his Planorbis-zone corresponds 

 to the upper part of our Ehgetic series, including the White Lias. 



19. Caedinia Suttonensis, spec. nov. PL lY. fig. 3. 



Shell transversely oblong, obovate ; ventral margin gently rounded ; 

 anterior end broadest, obtuse ; posterior end subaeutely rounded. 

 Surface with deep, concentric, distant hues of growth, and smaller, 

 elevated, intervening strise, which become less distinct at the posterior 

 end. Umbones somewhat acute, placed about one-fourth of the length 

 from the anterior end. Length 2\ inches ; breadth |-rds of length. 



Locality and position. — Sutton quarries, Sutton series. 



This shell is nearest in form to C. regularis, Terquem ; but the 

 posterior end is more acute than in that species ; the size is also 

 larger, and the shell thicker. It is less cuneiform than C. acuminata, 

 Martin, to which it bears some resemblance. 



20. Caedinia ingens, spec. nov. PI. lY. fig. 2. 



This large cast of the interior is from the Sutton series near 

 Langan. My specimens do not show the outside of the shell. AU 

 that I saw with the outside shell were in an earthy condition and 



