Holotype: Shell small for the subgenus, uniformly grayish black, aperture blue-gray within, surface texture waxen; subsutural area concave; suture marked by a narrow, undulating cord with another, slightly more prominent cord below. Protoconch of 2 smooth whorls, postnuclear whorls 9. Axial ribs 13 on early and final whorls, flexed to the right at the shoulder and extending across the base; back of last whorl with a stronger axial rib 1/8 turn back from the lip; spiral sculpture of 3 additional grooves in the concave subsutural area and regularly spaced grooves on the upper half of the body whorl, changing to broad, straplike cording on the lower half, producing lighter colored beads on crossing the narrow axial ribs on the lower half; pillar with narrow, raised cords. Sinus deep, U-shaped, bordered on the inside by curved parietal callus showing incremental layering; lip edge moderately thick, stromboid notch faint; anterior end truncate, weakly notched, inner lip raised above the pillar. Height, 11.0, diameter, 4.7 mm.

Although of the same general form as Crassispira coelata (Hinds, 1843), with which it occurs, C. martiae differs in being broader with a more tabulate outline and having a less pronounced subsutural cord. Axial sculpture is stronger in these two species than in other Dallspiras, but the sinus is characteristic of that group.

Tropical East Pacific. Type Locality: Venado Island, Panama Canal Zone.