TAB. XXIV. 



Fig. 



1. Lutraria elliptica, p. 251. From Coralline Crag, Ramsholt. 



2. Mactra truncata, p. 245. 



3. Mactra subtruncata, p. 247. 



a, specimen from Sutton. 



b, specimen from Bramerton. 



4. Mactra solida, p. 245. From Red Crag, Sutton. 



c, a triangular variety probably of this species. It much resembles M. striata, 

 Smith, 'Wern. Trans./ vol. viii, pi. 1, fig. 22, but it has the two sides more 

 equal. 



5. Mactra obtruncata, p. 248. From Red Crag, Sutton. 



6. Mactra constricta, p. 249. 



7. Mactra deaurata, p. 249. 



8. Mactra procrassa, p. 244. 



