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The most constant feature in Buccinum is the spiral 

 sculpture by which I inean the minute sculpture exclusive 

 of the large raised spiral ribs or cariuae, which as I have 

 said are extremely variable. This was also the conclusion 

 of Stimpson after much study. 



There are occasional hybrids and in species like B. 

 glaciale with the coarser kind of spiral sculpture , it is 

 occasionally stronger or fainter in some individuals thau in 

 others, but when well developed and perfect [ have never 

 had any trouble in recognizing the species by it. It will 

 be seen that from the dead, beachworn, eroded material 

 usually found in collections it will be by no means easy 



/to determine the species; nor would it be much better 

 with a bird which had lost its head, fee£, and part of its 

 tail, and had been used as a scriubbing-brush for so nie 

 weeks. 



It may be thought that the idea I have in my mind 

 of what constitutes a species in the genus Buccinum is 

 very wide and not sufficient to serve as a guide for others. 

 This may be true; but it seems to nie much more satis- 

 factory to be able to group arouud a definable parent-form, 

 in regularly assigned places, the varietal offshoots from 

 that parent-form and thus to recognize in the nomen- 

 clature not merely the relations between. parent-form and 

 varieties (as involved in the expressiou of „connection") 

 but also the way by which the varietal characters deve- 

 loped, the reason why particular ones were preserved and 

 the uniformity throughout the genus of tendencies in cer- 

 tain recognizable varietation-lines. Another generalization 

 may be permitted. When the tendency in an individual is 

 to strong sculpture, generally not ouly the carinations but 

 the longitudine ribs will be strong, but when these last 

 are not so, there is generally a node or lump on the carinae 

 where the intersections would have otherwise occurred. 



