181 



and of which only one species, C. elongata, referred by Lamarck to Psam- 

 mobia, had been previously described. The hinge scarcely differs from 

 that of Soletettina, except in the teeth being more developed, and in the 

 oblong callosity or fulcrum being less prominent ; but the species present 

 a very natural assimilation of external characters. They are all of a uni- 

 form transversely oblong growth, with the posterior side simply truncated 

 into a faintly obtuse angle. 



1. Candida, Reeve. 



2. Chinensis, Des/i. 



3. crassula, id. 



4. difficilis, id. 



5. elongata, Lam. 



6. Layardi, Desk. 



Species. 



7. lunulata, Desk. 



8. minor, id. 



9. radiata, id. 



10. rosacea, id. 



11. rufa, id. 



12. solenella, Desk. 



13. solida, Reeve. 



14. tenuis, Desk. 



15. virescens, id. 



16. violacea, Reeve. 



Figure. 



Capsella radiata. PI. 38. Fig. £07. Shell, showing the transversely 

 oblong form and faint posterior angulation. 



Genus 11. SOLETELLINA, Be Blainville. 



Animal; undescribed. 



Shell ; transversely oblong, compressed, mostly equivalve, nearly 

 equilateral, covered with a horny epidermis, gaping a little at 

 the sides, the posterior sometimes acuminated, sometimes shortly 

 truncated ; hinge composed of a single erect tooth in the left 

 valve and two in the right valve, sometimes bifurcated, with a 

 conspicuous fulcrum in each supporting the ligament. 



Pounded by Blainville on the Linnean Solen diphos, and remodelled 

 with excellent discrimination by M. Deshayes, the shells partaking rather 

 more of the characters of the Solenacea than the preceding genus. The 

 typical forms are elongately oblong and depressed, with the posterior side 

 sometimes acuminated, and they are of a peculiarly sombre leaden-violet 

 colour, covered with an olive horny epidermis. Another type, represented by 

 8. Nuttallii, is of an obliquely orbicular form. The first of these types in- 

 habits the Eastern Seas, the second inhabits California. S. orbiculata 



