"STROPHIA INFLATA.

Swollen Strophia.

Plate VII, 21 & 21 a, shell: FIG. 30; A, front, B, left side. DESCRIPTION.

            SP. CH. Size, medium. Shell heavy. Striations are absent. Whirls, 10. Teeth, two, and short. Examined 25 specimens.

            Form of shell, cylindrical, with the second and third whirls the largest in diameter, the first and fourth are a little smaller, the fifth is considerably smaller than the fourth, and from this, the shell slopes rapidly to a blunt round­ed, nearly hemispherical apex, forming a wide angle of nearly 90 degrees. The surface is pol­ished but is slightly furrowed with lines of growth, which are much less prominent on the lower whirls. The sutures are shallow, and the whirls between them are slightly bulging.

            Aperture, of medium size but open, and measures considerably more just within than at the entrance. Lower tooth, very slightly de­veloped and is raised by gradual elevation from the surrounding surface. It is about .10 long. The upper is situated considerably above, is about as prominent, but is more conspicuous within.

            Margin, not produced forward as far as the diameter of the shell, is inclined slightly backward and a little to the right: it is not thickened and the outer portion is produced into a thin but not prominent edge which is not rolled downward. The frontal bar is not prominent, being

interrupted in the middle.

            Color of shell externally, white, conspicuously striped with yellow­ish brown that becomes nearly yellow on the lower whirls, and which occupies the last two, whol1y excluding the white. The margin, frontal bar, and teeth are yellowish, and on the lower wall, within the aperture, are purplish brown stripes that merge into the universal purplish brown of the interior.

DIMENSIONS.

            Size of types, .90 by .35. Largest specimen, 1.00 by 37; smallest, .90 by .36. Longest specimen, 1.00; shortest, .90. Greatest diameter, .37; smallest, .35.

OBSERVATIONS.

            Although in some specimens the first whirl is but little smaller than the second, it is always some smaller, and in the majority of cases, noticeably so, and also in many instances, the third whirl is larger than the second. There is a decided inclination among some individuals, to have the margin slope considerably backward, thus possible constitut­ing a form. The markings described are very constant, as well as the number of whirls.

            This well marked species may be at once distinguished from the short toothed Strophias, by the inflated lower portion, absence of stria­tions, heavy shell, and stripings.

DISTRIBUTION AND HABITS.

            The Swollen Strophias occur at Salena Point, Auklin Islands, Ba­hamas, where they were collected by Dr. Henry Bryant of Boston, many years ago. I obtained the specimens from which I made the above de­scription, from the collection of the Boston Society of Natural History, where through the courtesy of Mr. Samuel Henshaw, I was permitted to examine the Strophias."