Drillia peripla: Shell small, rough, dark-colored (normally?), acute, nine-whorled ; nucleus and two and a half nuclear whorls yellowish, with sculpture reticulated by raised revolving lines, and lines waved backward from before and behind a point on the periphery; remainder of the shell transversely sculptured by twelve or (on the last whorl) fourteen rounded ribs, which start at the anterior bonier of the band, where they are roundly shouldered, and continue somewhat obliquely to the suture, or, on the last whorl, to the anterior third, narrowing as they go ; beside these, the lines of growth are well exhibited and the notch-band is ornamented by distinctly raised, transverse, backwardly concave plications, which extend across it, about nine in the space of a millimeter, with wider interspaces; spiral sculpture consisting of (on the smaller whorls) three to (on the last whorl) about nine raised rounded riblets, the first of which is just in advance of the band, and between every pair of which are two (or in rare cases) three much finer threads; the primary threads are a little swollen where they cross the transverse riblets, the secondary threads not so ; toward the anterior end of the canal the threads become uniform in size and are crowded together ; the threads, especially the secondary ones, have a rough appearance, perhaps due to the lines of growth ; aperture (excluding the canal) ovate, somewhat abruptly compressed to form the very distinct straight canal; pillar straight, without callus ; outer lip imperfect in the specimen, but probably thickened in the adult. Lon. of shell, 8.0 ; of last whorl, 4.75; of aperture and canal, 3.5. Max. lat. of shell, 3.25 ; of aperture, 1.5 mm. Defl. about 34°.
Yucatan Strait, 640 fms.
The specimen is light brown, blotched with a darker shade, but it is doubt¬ful if# this is not accidental to the specimen. The abrupt contraction to form the canal gives it the aspect of a little Fusus.

Watson's description being based on a broken worn shell and the illustration of the protoconch being incorrect, a new description based on the BIOGAS specimen is presented below.
Shell high, slender, white. The larval shell consists of at least three convex, rapidly increasing whorls, with an oblique, reticulated sculpture; its colour is dark yellowish brown and it is about 800 µm high. This specimen has 7.5 rather slowly increasing postlarval whorls. The suture is distinct, but not very deep. The subsutural zone occupies a little more than one fourth of the height of the whorls, it is distinctly concave and sculptured by deeply sinuated incremental lines. The axial sculpture consists of incremental lines and big rounded axial ribs. The incremental lines are not very distinct and of varying strength, they are strongly and regularly curved, more curved than the ribs which arc obliquely placed and only very slightly curved, more curved than the ribs which are obliquely placed and only very slightly curved. They are highest just below the subsutural zone, where they start almost as a knob, then they get lower and disappear more or less at the lower suture. The spiral sculpture consists of low ribs, a little irregularly running and V-shaped in cross-section. There are 11 on the penultimate whorl and a single one on the first postlarval whorl. The parietal callus is thin and covers about one fourth of the columella. The siphonal canal is deep and rather long. Dimensions: height of the shell 24.0 mm, breadth 9.0 mm; height of the aperture 10.2 mm, breadth 4.2 mm.

Remarks. The animal lacks an operculum and is blind.
It differs from most Gymnobela species by its low aperture and slender, slightly concave spire. It comes closest to G. pyrrhogramma but the colour of the shell, the spiral sculpture and radula make separation easy. Also G. pyrrhogramma has eyes.

Drillia peripla: Yucatan Streat. Mexico. Cuba.