GENUS DOLIUM. 3 



to the state in which Linnaeus had left them : he places them 

 between HARPA and BUCCINUM. De Blainville has arranged 

 them in his family Entomostomata, between HARPA and CASSI- 

 DARIA. This writer divides them into three sections : first, 

 species having an ovate form, spire pretty prominent, right lip 

 always thin, such as the DOLIUM perdix and rufum (I consider 

 this last species only as a variety of the perdix, or as an injured 

 specimen) ; second, those with a short spire, more ovate and 

 more globular, of which the galea and olearium, present exam- 

 ples; third, the Cassis-formed tuns, always oval, more or less 

 globular, with very distant ribs, the right lip bordered, and the 

 columella twisted at its extremity, such as the DOLIUM macula- 

 turn^ fasciatum, variegatum and pomum. 



Latreille, in his work, Families Naturelles, fyc., includes the 

 Tuns, the Harps, and several other genera in a single family of 

 his order Gasteropoda, to which he gives the name of Dolium- 

 formed. I agree, in some respects, with the opinion of this 

 writer, that the approximation which he makes of the Harps and 

 the Tuns appears natural, and founded upon a very important 

 character, that of the absence of the operculum in both genera. 

 But, I think that they should form not one family, but a separate 

 division, and therefore I shall class them among the Purpurifera, 

 of which they should certainly make a part, on account of their 

 affinity to all the other genera comprised in this family. I retain 

 for my division the term Dolium-formed, because I separate from 

 the family of the same name, the genera MONOCEROS, CONCHO- 

 LEPAS, and PURPURA, which I refer to the Buccinoidea of the 

 same author. 



With regard to the divisions which De Blainville has establish- 

 ed in the genus which I am examining, I think they are founded 

 upon characters too variable and too superficial for me possibly 

 to adopt. I have replaced them by the two groups of which I 

 have spoken, and which I thus characterize : the first, with the 

 right lip always thin, and undulated ; the second, with the right 

 lip more or less thickened by the margin, and pretty strongly 

 denticulated. I have thought that a shell which Valenciennes 

 had determined under the generic name of MALEA, (Recueil 

 ff Observations de Zoologie, Humb. et Bonpland, p. 325), ought 



