A REVIEW OF THE AMERICAN VOLUTIDZ 
By WILLIAM HEALEY DALL 
In making a complete examination of the synonymy and various 
classifications proposed for the Volutidz, it became evident that 
serious difficulties were in the way of a final revision of the whole 
group, on account of the obstacles to obtaining full data on many 
of the exotic genera, the habit of dealers in destroying with acid 
the characteristics of the nuclear shell, and the inaccessibility of 
some of the rarer species. 
While the collection of Volutes belonging to the National Museum 
is fairly good, that portion of it relating to the American species is 
not only nearly complete as regards the several species, but it also 
contains large and unmutilated series of many of them. It was evi-- 
dent, therefore, that a review of the American forms was quite prac- 
ticable, while a more complete revision must await fuller data and 
might be subject to much delay. I therefore decided to prepare the 
present paper. ' 
Some sixteen years ago I was able, from a study of the recent 
and fossil species of our Atlantic coasts, to point out that the family 
was naturally divided into two great groups, in one of which the 
protoconch is membranous and is lost early in the intracapsular 
development of the young, being replaced by a shelly envelope 
which carries traces, when intact, of its secondary origin. In the 
other the protoconch is shelly from the beginning, often sculptured, 
and is never naturally lost except by mechanical erosion in the adult 
shell after it leaves its ovicapsule. These two series I distinguished 
as subfamilies Volutine and Scaphelline after their most charac- 
teristic genera. The latter name, however, I have since found to be 
inapplicable, because the real type of the genus Scaphella is not the 
species, I then supposed, but belongs to the Volutine. I now sub- 
stitute for the second subfamily the name Caricelline, the genus 
Caricella of our Eocene being the ancestor of the North American 
series of Volutes with a membranous protoconch. 
During recent years some very important data in regard to the 
anatomy of various species has been gathered and it is evident that 
while certain geographical groups of Volutes are doubtless homo- 
geneous some of the species of which only the shell had been known 
are possessed of markedly distinctive characteristics. 
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