Strophiops faxoni Maynard, 1896

Original Description


Faxon's Strophia.

Plate VII, fig. 1 front, fig. 2, side view of type.


            SP. CH. Size large for this sub-genus (Umbonis). Striations, present, shell rather thin. Whirls, 11, the upper of which, including margin, is as long as the next four.

            Form of shell an oblong turret, with the first two whirls about equal in diameter, from the second, the shell slopes to an acute point, forming an angle of about forty degrees. The striations are few, thir­teen to the first whirl, very prominent, bulging, not greatly enlarged in the middle, regular and crooked, and not arranged in lines. They are not an equal distance apart, but the interspaces between them are

always twice as wide as the prominences; and there are longitudinal sub-striations indicated in some of the depressions. Both striations and interspaces are crossed by narrow, transverse lines, which are, however, everywhere about an equal distance apart, without any un­marked interruptions in the center of the whirls. These lines are about .01 apart, and there are about twenty of them on the first whirl beneath the frontal bar. The suture is deep.

            Aperture, not very small, about as high as wide and open. The lower tooth is not prominent, rising gradually from the floor of the mouth, is about twice as long as high; it is about central in position, and is set back about once its length from the frontal bar. The upper tooth begins a little back of the lower, is about its size, and is placed low on the column.

            The margin is not produced quite as far forward as the diameter of the shell, is inclined backward on the upper left side, and the lower right further than on the corresponding portions on the opposite side, in this respect resembling S. scalarina, hence this peculiarity becomes sub-generic. It is considerably flanging, especially on the right side, about .07, and here it is somewhat roughened by minute tubercles which are arranged in radiating or transverse lines. The frontal bar

is very prominent, extending well out beyond the shell. The trans­verse striations appear on the right side of the tooth, and continue far within the shell.

            Color of shell, pale yellowish, externally, but the specimens have evidently been cleaned and thus the transverse lines do not contain any soil. Within, very pale yellowish, becoming white on the margin.


            Size of type, 1.12 by .40; size of one other specimen examined, 1.20 by .40.


            Rather singularly after my article upon S. scalarina was in type, I found two specimens of S. faxoni in the museum collection of which I have just described, thus confirming my theory that there must be more species found of this remarkable sub-genus, for, although these speci­mens were simply labeled " Cuba, " I have no doubt but what they came from the neighborhood of Gibara, Cuba.

            S. faxoni differs from S. scalarina not only in being at least three times as large, but also in other important particulars. The form of' the shell is rather different, the first two whirls being about equal in diameter, the margin is more flanging, and on the right side has the pe­culiar minute tubercles, arranged in lines. The striations are also quite different, being irregular, narrower and crooked, and not enlarged in the middle. I have named this species for Dr. Walter Faxon, who has dis­played the utmost interest in my work upon Strophia, and also has kindly aided me in many ways."

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