1865.] TAWNEY RH^TIC BEDS AND SUTTON STONE. 83 



7. Lima planicostata, spec. nov. PI. III. fig. 7. 



Shell ovate, oblique, moderately convex, considerably longer than 

 broad. Surface of shell with distinct concentric lines of growth and 

 very faint radiating striae, which are most marked on the posterior 

 part of the shell. Ears unequal, the posterior largest. Length f 

 to 1| inch ; breadth |-ths of length. 



Locality and position. — Sutton series at Laleston and Sutton &c. 



This shell dift'ersfrom L. prcecursor in form, and by the absence of 

 depressions in the interspaces between the ribs. It has some re- 

 semblance to L. compressa, Terquem, and to L. acuta, Stopp. ; but the 

 sculpturing of those species renders them very distinct. 



8. Lima angusta, spec. nov. PI. III. fig. 6. 



Shell moderately convex, elongated, obliquely oval, inequilateral, 

 most arched in the centre. Anterior side straight for five-sixths of 

 its length and nearly parallel to the longer axis of the shell. Poste- 

 rior margin swollen in the centre and slightly concave below the ear. 

 Surface with regular, not very close or deep, radiating lines, eon- 

 centric striae, and lines of growth, which cross over the flat ribs. Au- 

 ricular areas sloping gradually into the umbo. Hinge-line straight. 

 No lunule. Length 2|-3 inches ; breadth |-ths of length. 



Locality and position. — Sutton series at Sutton and Dunraven. 



My examples of this shell are rather weathered, so that the sur- 

 face-markings are not so well preserved as could be wished. 



The form of this shell is characteristic. The shell that approaches 

 nearest to it is L. prcelonga, Martin, from the Angulatus-zone of the 

 Department of Cote d'Or. 



9. Lima subduplicata, spec. nov. PI. III. fig. 8. 



Shell ovate, slightly oblique, narrow at the hinge-line, convex. 

 Eibs about 25, elevated, not sharp ; on the anterior and posterior 

 sides they become narrower and sharper, and the interspaces wider ; 

 interspaces with a fine costa between each of the ribs. Length J to 

 1 inch ; breadth |rds of length. 



Locality and position. — Sutton and Southerndown series at Sutton 

 &LC. Common. 



The exterior of the shell is frequently lost, and the costae are then 

 invisible. 



Closely allied to L. duplicata (Great Oolite): it corresponds exactly 

 in form, but the line on the ribs is apparently absent. In its mature 

 state it is much smaller than L. pectinoides, neither are the ribs so 

 sharp, and the interspaces are broader than in that species. It resem- 

 bles an unnamed species figured by Quenstedt (Jura, p. 47, pi. iv.). 



10. Lima Dunravenensis, spec. nov. PI. III. fig. 9. 



Shell moderately convex, obliquely oval. Anterior side straight 

 for four-fifths of its length, and curving round suddenly into the in- 

 ferior margin, which is strongly convex. Surface with numerous 

 fine, sHghtly wavy radiating lines, crossed by a few concentric lines 

 of growth. Length 3 J inches ; breadth -|ths of length. 



