620 APPENDIX. 



Vol. i. p. 181. Genus COLUMBELLA. 



Some of the species of the sub-genera Nitidella and Mitrella 

 have the operculum like that of Purpura. These groups should 

 therefore form a genus in the suh-family Purpurinoe, under the 

 name of Mitrella. 



Vol. i. p. 192. Genus PERSICULA. 



Sub-gen. eabicea, Gray. 



Shell with the inner lip callous, with a large cross fold in 

 front; outer lip crenulated. P. interruptolineata (inter rupta, 

 Lam.) is an example. 



Vol. i. p. 197. Genus RINGIOULA. 



According to the recent observations of Mr. Woodward, the 

 animal of this genus is like that of Action, and the lingual den- 

 tition similar to that of Philine and Scaphander. It should 

 therefore be removed to the family Actcconidm. 



Vol. i. p. 200. Fam. LAMELLAKILD.E. 



M. Rudolph Bergh in his "Monograph of Marsenida" has 

 distributed the species as follows. 



Genus MARSENIA, Leach. 



Shell internal, spiral. Mantle not cloven in front. 

 Seventeen species. 



Sub-gen. chelinotus, Swainson. 



Mantle cloven in front. 

 Four species. 



Genus ONCHIDIOPSIS, Beck. 



Shell internal, not spiral. 

 Two species. 



