MONOCEROS. 



nearly related to many Purpuras ; there cannot exist a 

 doubt, that like them they have an operculum : above we 

 have shown the principal distinguishing character : but 

 Monoceros also very nearly resembles the Concholepas, a 

 shell included by Bruguiere in Buccinum, but placed by 

 Lamarck among the PatellaB ; the testimony which is borne 

 by several, to the fact of this last-mentioned shell possess- 

 ing an operculum, compels us to believe, that it is much 

 - more nearly related to Purpura and Monoceros, and that 

 it should therefore be placed in the same family with them. 



The recent species of this Genus of marine shells, are 

 not numerous ; it is with difficulty that some of them are 

 distinguished, because, like the Purpuras, they are subject 

 to so much variation. A single fossil species is figured by 

 Bruguiere under the name of Buccinum monacanthos : it 

 is the only one we know of. 



Fig. 1. Represents Monoceros imiricatum^ a shell which is far from being 

 common, though perhaps the most frequent of the Genus. 



2. Represents a shell, which dilTers from M. imhricatum in having a 

 short spire, scarcely produced beyond the upper part of the last 

 whorl: we consider it as only a variety: it is not essential to the 

 nature of this work, that we should decide this point ; if it be a dis- 

 tinct species; Jrere would be a suitable name. 



3. Nearly resembles the figure given in the Encycl. Method, of M. eras- 

 silabrum. Lam. We avoid speaking with certainty to this point, be- 

 cause we have no description to refer to : we think it distinct, and if 

 it prove so, we should suggest the specific name of lugubre. 



4. Monoceros cingulatum^ Lam. a very curious and uncommon species 

 in which the inner part of the lower volution is not abraded, as it is 

 in the others, 



Besides these, the three last of which are in Mr. f)u- 

 bois's collection, we have seen several other very distinct 

 species in the same collection, and some in Mrs. Mawe's, 



