ACT.^ON. 



433 



partly testaceous, as in Odosfomia) : spire small, with the nr. - 

 cleiis on the inner side at the base of the shell, ear-shaped, and 

 defined or separated from the greater part of the operculum by 

 a furrow on the upper- and a ridge on the underside. 



This generic name and its synonym Tornatella were 

 applied by Grateloup, Nyst, and Sismonda to species of 

 Odostomia ; and their shells have certainly a degree of 

 similarity. But the apex of the spire in Actceon is re- 

 gular^ instead of being reversed ; and the animal is dif- 

 ferent from that of Odostomia. (See page 110 of this 

 volume.) Nearly twenty years ago Mr. Alder pointed 

 out the affinity of Actceon to Bulla ; and his views have 

 been confirmed by the observations of other conch olo- 

 gists. Indeed Linne at first placed our typical species 

 in Bulla, although he afterwards removed it to Voluta. 

 The operculum was described by Turton, in his little 

 treatise entitled '' Conchology_, arranged on the amended 

 system/' which was published in 1829. Delle Chiaje 

 was the first to make known the animal. The present 

 genus exhibits also a slight analogy to Melampus ; but 

 the spire of that shell is hollow^ and has no internal 

 partition. 



Actceon has an extensive distribution, both in time 

 and place ; according to Woodward it comprises 16 

 recent and 70 fossil species. 



It is the genus Tornatella of Lamarck and Speo of 

 Hisso. The name Actceon was used by Oken (subse- 

 quently to De Montfort's work) for a genus allied to 

 Aplysia, which is now recognized as the Elysia of Risso. 



Action torna'tilis"^, Linne. 



Fohifa tornatilis, Linn. S. N. p. 1187. Tornatella fasciaf a, F. & H. iii. 

 p. 523, pi. cxiv. D. f. 3, and (animal) pi. VY. f. 7, as T. iornatilis. 



Body pale yeUowish-white, with a slight purplish tint and 



* Turned in a lathe. 

 VOL. IV. XJ 



