Perforate Dome

(A. Binney, 1843)

Ventridens demissus







Taxonomic Information

Helix demissa

Original Combination:


Original Description:

Depressed-convex; epidermis yellowish horn color, shining; whorls six, with minute lines of growth; spire obtuse; suture impressed; body whorl expanding very little towards the aperture; aperture transverse, not large, a white testaceous deposit within; lip thin, acute; base rather flat, smooth; umbilicus very small, umbilical region a little impressed.
Greatest transverse diameter rather more than three eights of an inch.
Geographical Distribution. The only specimens which I have yet seen were procured in the western part of Pennsylvania.
Remarks. This is a delicate and very pretty species, and is distinct from everything unless it be Helix lingera. The character of the surface and skin is the same in both, and the base is nearly the same. I have seen very depressed specimens of Helix ligera, but none approaching this. It may, however, be subject to still further reproductions in the height of the spire, until it reaches the depression of the present shell. If it should be the same, it will exhibit very extraordinary variation in this respect, from a high conical to planulate form. It resembles Helix suppressa externally in everything except size.

Original Description Citation:

Binney, A. (1843). Descriptions of two undescribed species of North American helices. Boston Journal of Natural History, 4(3): 360-362, plates 16, 20.

Ecological Information



Nature Serve Conservation Status:

G5: Secure