MONOGRAPH OF THE GENUS STROPHIA. 
21 
downward. The frontal bar is not well developed, and the striations 
appear within it, but beneath the translucent enamelling of the lower 
wall, and are thus not elevated. The animal is not very large; eye pe- 
duncles, .12 long; tentacles, .04. 
Color of shell externally, white, with mest of the interspaces between 
the striations, dull purplish brown; internally, of rather a pale purplish 
brown which becomes paler on the lower w~all of the aperture, and fades 
on the upper walls and teeth, into yellowish white. Color of animal, very 
dark brown, with the bottom of foot, eye peduncles, tentacles, and top 
of head in front of tentacles, horn color. 
DIMENSIONS. 
Size of types, 1.04 by .40 and .98 by .42. Largest specimen, 1.10 by 
.46; smallest, .74 by .36. Greatest diameter, .46; smallest, .36. Longest 
specimen, 1.10; shortest, .74. 
OBSERVATIONS. 
Individual variation is not great, the type form being very constant. 
Two forms occur besides, one of about the same ferm, but with the aper- 
ture inclined well to the right, and the shell is larger, thicker, and whiter, 
with fewer markings; while the other is shorter and proportionally a little 
thicker, with the markings in some instances, extending across the 
striations. The margin is never heavy, .08 being the extreme meas- 
urement. Striations vary from 18 to 20. 
Known from S. copia, its nearest ally, by the prominent markings, 
and from all others, by these and the long teeth. 
DISTRIBUTION AND HABITS. 
I found the Lined Strophia in a small cocoa-nut grove on the south 
side of Little Caym'an, near the east end, and more rarely in the cocoa- 
nut grove near the boat landing, on the south side of Cayman Brae, 
This spot on Little Cayman, about a half acre, was occupied by them 
exclusively, while on the other key, they mingled with the Common 
Strophias. They were probably transported from one place to the other 
by boat, the original locality, probably, being Little Cayman. 
The cocoa-nut grove where I found these Strophias, was situated 
directly on the shore, some miles from any settlement, and was com- 
pletely isolated from all other colonies of Strophias. The width of the 
key intervened between this point and a colony of S. copia on the north 
shore, two miles, at least, of nearly naked, jagged rocks, as impassable 
to a mollusk of this species, as would be the wide Atlantic, and there 
was no vegetation in this direction, to induce them to extend their 
