Cerion grisea Maynard, 1894

Original Description

 

"STROPHIA GLANS GRISEA Novo.

Gray Acorn Strophia.

Fig. 51, A, front view of type, B, margin of same.

DESCRIPTION.

            SP. CH. Size, medium. Shell, heavy. Striations present. Whirls, ten. Examined 200 specimens.

            Form of shell, cylindrical oval, the first and second whirls being the largest and about equal in diameter, then the shell slopes to a rather acute point, forming an angle of sixty-five degrees. The striations are rather numerous, twenty-five to the first whirl. They are not prominent, narrow, not wider than the interspaces between them, are regular, inclined to be arranged in lines and rounded. but not polished.

            Aperture, small, about as wide as high, rather contracted at the entrance. Lower tooth, prominent, oval, about .05 high, as wide as high and not quite as long as high, it is not

placed far back, not once its length, and is not elevated. The  upper tooth is a mere tubercle and is placed low, not higher than the top of the lower tooth.

            Margin, produced about as far forward as the diameter of the shell, is placed a little to the right of the center of the shell and is inclined slightly to the right. It is thick (.12), beveled, and grooved. The frontal bar is not very well developed, is thin, not over .02 thick, but completely interrupts the striations.

            Color of shell, externally, grayish ash, striations and all; ashy brown, within, which color extends over the teeth, where it is paler, however, and quite to the edge of the margin.

DIMENSIONS.

            Size of type, 1.10 by .45. Largest specimen, 1.15 by .47; smallest, .95 by .40. Greatest diameter, .47; smallest, .40. Longest specimen, 1.15; shortest, .95.

OBSERVATIONS

            As far as the specimeus which came from the type locality are concerned, this is a very uniform form of shell, there being only a slight individual variation in form and a little in color internally, but the peculiar gray tint of the external surface is very constant and characteristic. Had I never seen shells from any other locality than from the fields north of Fresh Creek, I should have unhesitatingly said that this was as strongly marked a species as I had ever seen, with strongly marked species, but it occurs in the fields on the south side of the Creek where it completely intergrades, through a small percentage of specimens with typical S. glans; hence I have been forced to consider it a sub-species.

            The Gray Acorn Strophia may be known at once by the thick, grooved margin, and peculiar uniform gray color which I have not seen in any other form of Strophia.

HABITS AND DISTRIBUTION.

            The first specimen of the Gray Acorn Strophia that I ever saw were brought to me by some Creole boys, but I soon discovered the typical locality, which were some fields north of the creek, about a mile from the settlement, and by the side of the road which leads northward to Calabash Bay. Here they were not common and were clinging to the bushes along the margin of the cultivated fields. South of the creek the few that I found were also clinging to bushes either in the fields or along the borders, but here they were even more rare than in the type locality. These specimens on the south side were undoubtedly transplanted from the north side through the agency of

the inhabitants, who pass from one set of fields to the other, carrying with them the plants of the casava on which the Strophias frequently occur."

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