82 



vexum,' late the 'nitidum'; both are in the vase with the 

 highly- punctured one captured 20th June last, now quite 

 vigorous, in company with the L. squamosum alluded to as 

 taken 2nd July ; this capture has given me the advantage of 

 a live examination of the two completely opposite conditions 

 of the ' convexum' whereas the one above was only referable 

 in comparison with an account of a live ' nitidum ' taken last 

 year. And I can again state that the two varieties are 

 identical. 



I give another proof of identity. I have just (1852) taken 

 alive a curious example, that shows one half of each valve 

 finely punctured and the other grossly granular. 



LUCINLD.E. 



This family has only one genus, Lucina, which includes 

 about eight species. Live specimens of the typical L, borealis 

 are of rare occurrence ; w r e have met with none for forty years 

 on the Devon coast, and of the L. rotundata only a small 

 example has been examined. Nor have the animals of the 

 L.flexuosa and L. ferruginosa been seen by us, but we receive 

 them sub fide Forbesii et Hanleyi. 



Since this was written, it will be seen below, that fortune 

 has been favourable, and enabled us to fill up some of the 

 gaps in the species of this family, but the curious incidents 

 attending it are so largely noticed in the descriptive history as 

 to dispense with further remarks. 



LUCINA, Bruguiere. 



L. ROTUNDATA, Montagu et nobis. 



Diplodonta rotundata, Brit. Moll. ii. p. 66, pi. 35. f. 6 ; (animal) pi. M. 

 f. 7. 



The present account of the species was written at Exmouth, 

 in the summer of 1849, and the reason of noting the date will 

 shortly appear. 



Animal lentiform, moderately thick ; mantle plain, some- 



