14 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 24, 



slightly carinated posteriorly, marked by numerous concentric ridges, 

 finely decussated by many radiating impressed lines, giving the sur- 

 face a punctated appearance. 



Locality. The Castle Kock, Scarborough. 



SOLEMTA WOODWAEDIANA, Sp. UOV. PI. III. fig. 7. 



Shell transverse, elliptical, compressed posteriorly, short and 

 rounded anteriorly ; the ribs (eight or nine) on the posterior side 

 prominent and granulated, those on the anterior side somewhat ob- 

 solete. 



This interesting species, of a comparatively rare recent genus, is 

 closely allied to the Solemya Voltzii, Roemer (Verst. Nord. Oolithen- 

 Gebirges, pi. 19. f. 20). 



Locality. North side of the Castle Rock, Scarborough. 



UificARDiuM SULCATUM, Leckcuby (Bean, MS.). PL III. fig. 11. 



Shell ovate, ventricose, inequilateral ; anterior and posterior sides 

 rounded, concentrically but irregularly sulcated ; umbones prominent. 

 Locality. South side of the Castle Eock, Scarborough. 



Caedium cognatum, Phillips. PL III. fig. 8a, 86. 

 We have figured a more perfect example than the type- specimen 

 of Professor Phillips, showing the ornamentation of the posterior 

 area. It was only by comparison with the original specimen that 

 the species could be identified. 



Caedium Ceawfoedii, sp. nov. PL III. fig. 9a, 9b. 

 Shell subequilateral, ventricose, compressed towards the margins ; 

 umbones prominent ; surface smooth, or with very faint concentric 

 striae ; the posterior area ornamented with about fifteen longitudinal 

 ribs; the middle ribs are the largest and more apart, and appear 

 somewhat scabrous ; they disappear or become quite faint before 

 reaching the posterior edge ; there is no definite ridge at the junction 

 of the posterior area with the dorsal surface ; the posterior margin 

 is slightly angulated, and its junction with the ventral margin well 

 defined ; this, and the anterior margin, are gently rounded. 



Named after Mr. W. B. Crawford, to whose exertions I am in- 

 debted for many fine specimens. 



Locality. The north side of the Castle Eock, Scarborough. 



IsocAEDiA (?) CLAEissiMA,Leckenby (Bean,MS.). PL III. fig. 10a, 105. 



Shell subtrigonal ; umbones prominent and incurved ; the surface 

 smooth where the shell remains ; posterior area flattened, its junc- 

 tion with the dorsal defined by a ridge ; anterior margin slightly 

 produced and gently rounded ; posterior margin angulated. 



Locality. The north side of the Castle Eock, Scarborough. 



P.S. I am indebted to Professor Morris for much valuable assist- 

 ance in the identification of species, and in preparing the descriptions 

 of several of the new ones. — J. L. 



