296 MURICID^. 



that prehensile organ was not used it did not get on so 

 well ! 



B. ciliatum, Fabr. With Scalaria Groenlandica, from 

 Shetland (Bean) : Greenland. See p. 97 of this volume. 



B. plicosum, 'M&nke^Fusm cinereus, Say=F. Forbesi, 

 Strickland. Isle of Man (Forbes) : Arctic Ocean and 

 United States. See vol. ii pp. 58 & 59. 



Dolium perdix, Linn. Weymouth (Pulteney) and 

 Jura (Laskey) : South-European and African. 



Cassis testiculus, Linn, (young) , B. decussatum, Penn. 

 = B. poyTatum^VxAi. Weymouth (Pennant) ; Firth of 

 Forth (Laskey) ; Plymouth (Lambert, fide Fleming) : 

 West-Indian. 



Family XXYIII. MUlirCIDiE, Fleming. 



Body spiral, usually long : mantle, pallial fold, head, and 

 proboscis as in the last family : tentacles forming an elongated 

 cone : ei/es on stalks, which are combined with the outer part 

 of the tentacles and placed some way up the latter : foot lan- 

 ceolate, longer than in the other family : opercidar lobe, gills, 

 and odontopliore as in the Buccinidce. Sexes separate. 



- Shell conic-oval or oblong, variously sculptured : spire pro- 

 duced : mouth oval : pillar not twisted : canal more or less 

 extended : opercidum horny, never spiral, increasing by semi- 

 elliptical or curved layers ; nucleus terminal. 



This huge collection of mollusca has been divided_, for 

 scientific convenience, into many genera, which are 

 distinguishable solely by their shells, never by their 

 soft parts. Still, mere conchological characters, and 

 even the structure of the operculum, are in some cases 

 not less useful for the purpose of classification than 

 characters based on the animal. Very few groups of 

 higher rank than species are equivalent, or can be coor- 

 dinated. I do not propose, on the one hand, to follow 



