140 
MONOGRAPH OF THE GENUS STROPHIA. 
Fig. 43. 
No. 2. Also short, but more slender, 1.06 by .60. Whirls, ten. 
Margin not produced forward any farther than the diameter of the 
shell. Striations, eighteen to the first whirl. The variation in one 
direction is toward a sub-form, with a less number of less distinct 
striations and a more cylindrical shell, and on the other hand, 
toward a greater number of more prominent striations, but with the 
form typical. There are rather more than two per cent, of this 
form. 
No. 3. A remarkable form, with a short, thick cylindrical shell, 
which, from the fourth whirl, slopes to a very blunt point, forming an 
angle of eighty-five degrees. Margin, teeth and color about as in form 
No. 1, excepting that the upper tooth is well developed. Striations, 
nineteen to the first whirl. See fig. 43, A. I have seen ten or twelve 
only of this remarkable form. 
Strophia grayi may be at once distinguished in the type form from 
S. ritchiei by the coarser, fewer striations and above all by the pro- 
jecting margin with its sharpened edge, which character will separate 
it also from all other Strophias which 
I have examined. In fact, in Strophia 
grayi this margin appears to have 
reached the maximum development 
and seems to be its strongest charac- 
ter. A specimen of form No 1 w hich 
has had the margin broken, has re- 
placed it with one that measures .30 
in length and which has the frontal 
bar projecting about .20 beyond the 
shell. See 43, B. It is a significant 
fact, that the central tooth, being no 
longer necessary with such a length of 
margin, has become nearly absorbed. 
There appears to be a great ten- 
dency among injured shells of this 
species to replace the broken parts with deformites, but as I intend to 
figure those peculiarities later, among others of other species, I will 
not enlarge upon them here. 
1 have named this species from Mr. Arthur F. Gray, of Boston, 
the wmll-known and accomplished conchologist 
IllUfn 
term 
B 
A 
A, Form No. 3, Strophia grayi. P, De- 
formed specimen of S. grayi. 
