Shell large, straw-colored with a tinge of rufous about the margin of the anal sulcus outside ; whorls 10-11 (seven remaining, nucleus and first normal turn broken away) ; whorls keeled or angulated at the periphery, the keel not riblike or sharp, but lightly rounded; in the first small whorls it is undulated or obscurely nodulous, but in the last four or five whorls not so ; from it the posterior part of the whorl ascends to the suture almost in a straight line or section of a cone, the anterior slope is full and rounded; the anal fasciole is polished and marked only by the fine silky incremental striae; the other transverse sculpture solely of fine incremental lines; spiral sculpture, beside the keel, of fine, rather angular threads (about seven in a space of 3.0 mm.) with a single finer thread generally present, on the last whorl, in the interspaces ; these cover the whole shell, which appears when quite perfect to have a thin dark olive-colored epidermis, of which only traces remain on the type ; aperture very large, the notch being one quarter of a volution in extent, very wide, and gently rounded into the outer lip, which is correspondingly curved forward ; canal short, wide, hardly differentiated from the aperture; columella nearly straight, a broad (in the type specimen) rather thick marginated callus extending from in front of the notch around on the body, well around behind the columella, and so on to the canal; in the type the edge of the callus is somewhat thickened and raised, but this seems to be due to senile degeneration. Max. lon. of shell (tip lost), 58.0 mm ; of last whorl, 45.0 mm; of aper-ture, 35.0 mm; diameter at broken tip, 1.5 mm; max. diameter, 25.0 mm.

This fine shell in its simplicity of sculpture and wide sweep of the peristome from the notch along the outer lip is quite unparalleled by any of the known species. Its nearest relative is P. Bairdii Verrill, which is stouter, with a much shorter spire and coarser spirals, beside having a shallow notch, distinct transverse ribbing, and no distinct carina. G. edgariana is much more spindle-shaped. It is named in honor of Mr. Edgar A. Smith, the well known conchologist of the British Museum. Gymnobela engonia Verrill, and some other forms which are considerably smaller, have somewhat the general aspect of this species, but all are stouter in proportion.

Caribbic. Near Curacao.