— 10 — 
The most constant feature in Buceinum is the spiral 
sculpture by which I mean the minute sculpture exclusive 
of the large raised spiral ribs or carinae, 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 than in 
others, but when well developed and perfect T 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 colleetions 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, feel and part of its 
tail, and had been used as a scrubbing-brush for some 
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 me much more satis- 
factory to be able to group around 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 expression 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 only the carinations but 
the longitudine ribs will be strong, but when these last 
are not so, there is generally a node or Zump on the carinae 
where the intersections would have otherwise occurred, 
