A rare, and undescribed shell, presenting a singular deviation from the general globose form of the Ampullariæ. The inner lip is wanting on the upper part of the aperture, and on the lower is thin, white, and reflected over the umbilicus, which is nearly obsolete.

Both these shells were in the late Mrs. Bligh's collection, without any habitat being affixed to them.


Pl. 137

PAPILIO Polybius.
Generic Character.—See Pl. 92.