114 PYRAMIDELLID^E. 



and Loven O. conoidea, and Malm O. albella. Again, 

 Turbo unidentatus of Montagu is a different species of 

 Odostomia from T. unidentatus of Turton, as well as from 

 0. unidentata of Fleming, while the shell described by 

 Hanley, in ( British Marine Conchology/ as the last- 

 named species, does not agree with any of the above. 

 But, as I ask forbearance for my own faults, 



Peccatis veniam poscentem reddere rursus. 



The geographical distribution of the species is very 

 extensive. Many species in public and private collec- 

 tions are undescribed, and an infinitely greater number 

 remains undiscovered in the South Atlantic, Indian, 

 Southern, and Pacific Oceans, notwithstanding the la- 

 bours of Philippi, A. Adams, Pfeiffer, C. B. Adams, 

 Gould, Stimpson, P. P. Carpenter and others. Few 

 species have been detected in the arctic seas ; and they 

 are equally rare in glacial deposits. The geological re- 

 lations of the genus have not been sufficiently inves- 

 tigated. 



The European species were placed by writers of the 

 Linnean school in Turbo, Helix, and Voluta; by the 

 followers of Lamarck they were assigned to Eulima, 

 Melania, Turritella, Phasianella, and Rissoa. 



The following synopsis may be useful for the more 

 easy discrimination of our native species : 



A. Oval or oblong, smooth, spirally striated, or (rarely) reti- 



culated ; pillar slightly curved, and invariably furnished 

 with a tooth. (Typical.) 1. minima ; 2. nivosa ; 3. trun- 

 catula ; 4. clavula ; 5. Lukisi ; 6. albella ; 7. rissoides ; 

 S.pallida; 9. conoidea; 10. umbilicaris ; 11. acuta; 12. 

 conspicua; 13. unidentata ; 14. turrita ; IS.plicata-, 16. 

 insculpta; 17 . diaphana ; 18. obliqua ; 19. dolioliformis ; 

 20. decussata. 



B. Elongated, longitudinally ribbed, or reticulated ; pillar 



