Shell thin, small, about 15 mm. in length, conical, elevated and somewhat narrower anteriorly. Front slope straight, posterior and lateral slopes slightly concave at the orifice and below continuing straight to the border. Apex a little in front of the middle, pierced by a small oblong anteriorly directed orifice which has a rounded tooth on each side. Its length is from one sixth to one seventh that of the shell. Sculpture consists of numerous, fine alternately larger and smaller radiating ribs, decussated by numerous concentric threads which form nodules or small scales where they intercept the ribs. Shell uniformly colored grayish white, cream or pale olive and sometimes with 4 or 8 irregularly placed darker rays. Margin finely crenulated, with paired denticles. Inside color the same as the outside, with the sculpture showing through as fine radiating and concentric white lines. Internal callus of the orifice sharply truncated and excavated behind, colored the same as the rest of the interior.

This species would appear to be near to the D. cayenensis complex, but actually it is not at all related. D. aguayoi is a thinner species and smaller than D. cayenensis. Its shape is different, having the posterior and lateral slopes concave near the apex and becoming straight toward the margin, a condition quite different from that found in D. cayenensis. The sculpture of D. aguayoi consists of alternately larger and smaller ribs which are separated by a narrow groove while in D. cayenensis the ribs are close set with every fourth larger than the three in between. Also, in D. aguayoi the orifice is in part flat on top and strongly angled on the anterior slope, a condition not occurring in any other Diodora existing in the Western Atlantic area. This species is only known from fairly deep water in depths between 80 and 450 fathoms.

Bermuda and south through the West Indies in fairly deep water.