MONOGRAPH OF THE GENUS STROPHIA. 
115 
neAv and a widely different standpoint from which it has been viewed in 
the past. The correctness of my judgment may be, possibly justly, 
questioned, but I do trust no one will venture to pass an unfavorable 
verdict whe has not been over the ground as completely as I have been 
over it, exploring those far away and often nearly desolate keys almost 
yard by yard, noting, and carefully recording, every attendant circum- 
stance and surrounding that can possibly have any bearing upon the lives 
of these interesting mollusks. I care not what experience one has had 
with other genera of shells, for while it is true that this may assist him 
in many ways, it does not fit him to pass positive judgment upon the 
work of one who has had an extended experience in a genus of shells so 
peculiar as is Strophia. For be it remembered, it is a portion of my 
heresy to believe that we cannot always form cut and dried rules that 
will apply to all groups of any one class of animals, even though these 
groups be closely allied. 
For an example, while we might, with perfect propriety, think a 
man very unscientific who would maintain that color variation, or the 
Weight of the shell of the common Purpura lapillus, of our coast, were 
of the slightest specific importance, yet both of these characters (color 
and weight) are of vast importance, as I have repeatedly shown, 
in Strophia. Color, in a species of Helix (IT. varia) which often 
grows side by side with species of Strophia, counts for nothing, 
specifically, as we find all gradations in this shell from pure white 
through a beautiful banded form to nearly black, nor is the weight of 
the shell of any great importance (although it may be somewhat so) 
in this species, nor is it, I believe, in any members of this genus. Why 
color should be important and protective in one group, and notin 
another, is difficult to say, but so it is. Nearly black specimens of the 
Varying Helix may be found side by side with white examples. 
Weight of shell means more with Strophia than with Jlelix as one 
animal (Flelix) has a muscular attachment and the other (Strophia) 
has not; thus members of the genus Strophia, with a changed weight of 
shell, naturally are obliged to assume other vital characters which need 
not be assumed by a Helix when it changes the weight of its shell. 
Hence one may be well posted in regard to all the changing ways and 
characters of even so closely an allied genus as Helix and yet know 
very little of the peculiarities of the members of the genus Strophia. 
But I think I have now said enough to convince any one that he 
ought, at least, to pause before giving an adverse opinion of my 
statements until he has seen as many of the members of the genus 
Strophia in their native islands as I have. 
