MONOGRAPH OF THE GENUS 



CONUS. 





In the following arrangement of species, I have endeavoured to 

 bring together those most nearly resembling each other, to facili- 

 tate comparison. Iu doing this I have found the gradations so 

 subtle as almost to defy any systematic division into defined 

 groups. There are no single characters which can be depended 

 upon with any certainty in determining the affinities and distinc- 

 tions either of groups or species. It is more by the eye, taking 

 in an assemblage of characters, and regarding the general appear- 

 ance, that they can be appreciated. Thus, although for conveni- 

 ence I have followed a prevailing custom in placing by themselves 

 in groups nearly all the coronated species, yet there still remain 

 some coronated species whose general characters forced me to 

 place them in widely different groups, while some generally coro- 

 nated species present varieties in which the whorls are smooth. 

 This is only one instance of what occurs with regard to almost 

 any character that can be named, such as length of spine, granu- 

 lation, etc. Under these circumstances it is impossible to main- 

 tain perfect consistency as to retaining and proposing some spe- 

 cies and rejecting others. As the collector's great object however 

 is to know the shells, I have preferred in most cases giving the 

 species as they stand, stating the alleged differences, and leaving 

 the final decision to individual taste. Thus, some eight or ten so- 

 called species of the textile group, are, to the best of my belief, 

 mere variations of one type ; yet I have admitted them in the cata- 

 logue, simply stating the points in which they are said to differ. 



a. Coronated, turbinated, straight-sided. 



1. imperialis, Linn. — C. oblongus, tuberculis magnis corona- 

 tus, medio subcontractus, versus basin attenuatus; albus, caeruleo 



VOL. III. B 



