400 MURICID^E. 



three in a row, the axile one broad and quadrate, with 

 many crenations, the laterals scythe-shaped, with denti- 

 culated bases. Male organ very large, sickle-shaped. 



We retain the old name Buccinum, originally applied 

 to whelks in general, for that group of shells, of which 

 the common Buccinum undafuni may be regarded as the 

 type. They constitute a very natural assemblage, though 

 one of no great extent, and are mainly inhabitants 

 of the boreal and arctic regions of both northern and 

 southern hemispheres. The relation of the distribution 

 of this form of ^lollusk to climate is strikingly shown 

 when we compare such a shell as the Buccinum cyanemn 

 of Greenland, with the Buccinum antarcticum of the 

 Falkland Islands, one of the most striking instances that 

 can be cited of the representation of species by similar 

 species in regions far apart, but subject to similar physical 

 conditions. 



Several zoologists have of late united the Buccinum 

 undatum and its allies with Fusus antiquus, and similar 

 shells, under the old generic name of Tritonium, originally 

 proposed by Otho Frederic Miiller. Independent of the 

 very serious objection which applied to this name on ac- 

 count of its having become obsolete, whilst the too simi- 

 lar word Triton, and even Tritonium itself, were used 

 in the meantime for a very different assemblage of Mu- 

 ricidfz, and one presenting good natural marks of dis- 

 tinction, we are inclined still, provisionally at least, to 

 keep up the distinction between the Fusi of the north 

 and Buccinum, since shell, animal, and operculum, pre- 

 sent marks of distinction, which^ though in the end they 

 may prove to be of no more than sectional value, yet in 

 the present state of our knowledge deserve to be con- 

 sidered of importance. 



