The shell is large for the genus (maximum length 21 mm ) and lanceolate. The spire is high and acute, consisting of two and three-quarters smooth, convex, gradually increasing nuclear whorls and six to eight dorsoventrally flattened postnuclear whorls. The suture, where not ohscured, is strongly impressed. The body whorl is relatively short and roughly fusoid. The aperture is small and ovate, with an imperceptible anal sulcus. The outer apertural lip is weakly erect, if at all; and bears a series of six weak denticles on its inner surface. The columellar lip is smooth and entirely adherent. The siphonal canal is short, narrowly open, and bent slightly to the left and dorsally.
The body whorl bears two well-developed varices laterally; each of these is thickened and narrowly expanded, if at all, and undulate. Two minor varices are also present, one dorsal to the right varix and one ventral to the left varix. In many specimens the minor varix dorsal to the right major varix becomes obsolete, leaving only three varices. Spiral sculpture consists of four to six low spiral cords on the body and ten to 12 cords of variable width on the siphonal canal. In well-preserved specimens from certain localities one or more rows of low, almost imperceptible pustules are apparent, following the weak spiral elements.
The shell is waxy yellow-white, in many specimens with a broad, red-brown spiral band on the upper half of each whorl. The aperture is porcelaneous white to yellowish, with red-brown staining on the labial denticles, especially in specimens with the spiral red-brown band. A layer of flat-white, finely axially striate intritacalx covers the shell in well-preserved specimens. The areas between the spiral cords are incised broadly into the intritacalx, this feature most evident on the leading edge of the varical flange.
Radwin & D'Attilio, 1976

A distinct form occurs endemically in the Galápagos Islands. Although almost certainly only a geographical variant of A. pyramidalis, it can be seen to differ consistently from the mainland form in its shorter, coarser body whorl, its shorter, more bent siphonal canal, its almost complete loss of the two minor lateral varices, and in having comparatively strong spiral sculpture with its associated pustules.
A. pyramidalis differs from other species of Aspella in its combination of large size and finely axially striate intritacalx, its color pattern (brown spiral band ), and its long protoconch.
Radwin & D'Attilio, 1976.

Maximum length is 21 mm.

Panamic faunal province from the southern Gulf of California to Colombia and the Galapagos Islands.