MONOGRAPH OP THE GENUS STROPHIA. 
189 
into a thin edge. The frontal bar is prominent enough to interrupt the 
striations. 
Color of shell, externally white, polished and shining internally and 
on the striations, within the aperture there is a faint tinging of yellowish. 
DIMENSIONS. 
Size of figured specimen, .87 by .37 . Largest specimen, .90 by -40, 
Jo by .36. Greatest diameter, .40, smallest, .35. Longest specimen, 
.30, shortest, .75. 
OBSERVATIONS. 
Among the shells of this singular species, that have passed through 
inv hands there is considerable variation m form, teeth, and m num 
her of striations. The widest departure from the types in regard to form 
is one m which the first four whirls are of the same diametei, then the 
shell tapers to a rather acute point. A second form has the first four 
whirls of the same diameter and with the apex rounded as in the type. 
Neither of these forms have the bulging appearance so characteristic 
of the species. It is remarkable that of two cylindrical shells before me 
one has one tooth only, and the other has none. This and the pointed 
form may each constitute a species, as it is possible that these characters 
are constant, and that the shells which are so marked come iiom diffei- 
ent locations. The specimen that I have figured came from the collection 
of the Boston Society of Natural History and was labeled as coming 
from Curacoa, while others which I have, nearly similar, are labeled 
as having been collected on Guadaloupe. The one-toothed and toothless 
specimens are simply labeled West Indies. ( See Eig 51, c. ) 
Typical shells of this species maybe at once recognized by the nar- 
row aperture, with the teeth close together, thus constituting a gioup, 
as noted on page 131, the narrow whirls with their prominent striations, 
arranged in regular lines, and the peculiar bulging form below the mid 
die of the shell. 
HISTORY AND DISTRIBUTION. 
This species, although the very oldest described shell of the genus, 
appears to have been recognized by many conchologists from the hist, 
while nearly all have described it correctly; where a figure has been given 
it is clearly of this species. I most heartily wish that the status of all 
of the older described species were as easily established as this. (In this 
connection see remarks under head of S. mumia. ) Xhis is somewhat 
remarkable, as the description given by Linnaeus most certainly could 
be applied to almost any of the smaller Strophias with striations, al- 
though to few, and not even to this, excepting to the form mentioned, 
can the term" apatura unidentata” (aperture one-toothed) be applied. 
