Strophia cylindrica Maynard, 1896

Original Description

"73 STROPHIA CYLINDRICA. Novo.

Cylindrical Strophia.

Plate VII, fig. 3, side, fig. 4, front view of type. DESCRIPTION.

SP. CH, Size medium, shell thick and heavy. Striations, present. Whirls, 10, the upper of which, including margin, about equal in width to the next four all together.

Form of shell, an obtusely pointed cylinder, with the first three whirls equal in diameter, the fourth is but little smaller and from this the shell slopes abruptly to an obtuse point, forming an angle of sixty degrees. The striations are numerous, twenty-four to the first whirl, they are not very prominent, straight, but slightly bent to the left on the suture, and they extend along it, tapering into a point; they are polished above, not furrowed, arranged in lines, and are of varying width, but are never wider than the interspaces between them. The suture is very shallow and very narrow.

Aperture, quite small, not open, nor contracted within. The lower tooth is not more than .03 high, and is about four times as long as high, is set back about .12 from the frontal bar. Behind this central tooth on either side the chancelled tooth begins and extends around the first whirl. The upper tooth is about as high as the lower and extends back around the column.

The margin extends forward as far as the diameter of the shell, is a little inclined backward and very slightly to the right, but scarcely beyond the diameter of the shell. It is not thickened, is rolled over, but not flanging and the edge is rounded. The frontal bar is quite well developed, yet the striations appear within it, but they are not very prominent and extend back far into the shell.

Color of shell, externally, shining white; within, deep purplish brown, pale on the tooth and internal striations. Margin, pale brown.

DIMENSIONS.

Size of type, 1.10 by .40. Largest specimen, 1.28 by .45; smallest .85 by .38. Longest specimen, 1.28; shortest, .85. Largest diameter .4:5, smallest, .35.

OBSERVATIONS.

Typical specimens are wholly white externally, but there is a strong inclination to become rosy at the apex, this feature is more prominent in the form given below. There are also other forms.

Form No. 1. Shorter, and proportionately stouter than the type. The apex is distinctly rosy and there are occasional lines of dark viola­ceous. This form exhibits a tendency on one hand to revert toward S. ianthina, and on the other toward S. rubicunda.

Form No.2. Very short, .85, with the margin thickened and bev­eled. Color similar to that of form No. 1.

Form No.3. Larger than the type, 1.28 by .45, with the margin much thickened, at least .75, and inclined to be double. Color, similar to that of the type.

Form No.4. More slender than the type, measuring .35 in diam­eter, white in color.

I cannot give the relative proportions of these forms nor their ex­act locations, as I did not make sufficiently, careful notes on them when I collected them.

This is the species which in many collections is labeled Pupa alve­aria, but erroneously, as I shall endeavor to show. The Turbo alvearia of Dillwin (Description Catalogue, II, page 315) was based partly upon the Alvearia buccinum of Seba and partly upon the Bulimus fusus of Burguiere (Encyclopedie Methodique, des vers, Vol. 1. page 348) hence

must be considered as a synonym of Bulimus fusus. What the Alvea­ria, buccinum of Seba was, is very doubtful, but it is quite probable that neither he nor Burguiere had a true Strophia in hand, when they made their description, and even if they had, their description does not apply to any Inagua shell with which I am aquainted. Dillwin dis­tinctly says his Turbo alvearia, was" white without and within" and this appears to be a correct interpretation of the authors upon whose de­scription he bases his specific characters. Now this does not apply to any Strophia from Inagua which I have seen, for all, without exception are colored within, none being white. even if they are wholly white exter­nally.

The name alvearia, having become a synonym is not again available in zoological nomenclature and, as shown, Bulimus fusus of Brugui­ere afterwards the Pupa fusus of more recent authors, probably is not a Strophia, but one of the peculiar members of the great family of Pupidae which occur in the Isle of France, to which locality it appears to be correctly assigned by Pfeiffer in his Monographia Helicorum Viventium, Vol. II. page 318, hence it remains for me to impose a new name upon the Inagua species.

DESCRIPTION AND HABITS.

I found the Cylindrical Strophia common in December, 1888, on the Island of Inagua, Bahamas. They were clinging to the trunks of small trees, just back of Matthewstown, and appeared to have a somewhat wide range, extending throughout the scrub lands from the town to the borders of the salina in the interior. December being a dry month, they were inactive, and firmly fastened to the trunks.

They appeared to avail themselves of any natural cavity and had often wedged themselves into these so firmly as to be removed with difficulty. They were always gathered in groups of from three or four to twenty individuals."

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