Original Description of Orthaulax caepa by Cooke, 1922, p. 31:
- "Shell large, heavy, circular in cross section; first six whorls, more or less, bare in juvenile shell but completely enveloped by subsequent whorls; callus-filled spaces between whorls evenly lunate in axial sections through the apex; apex conical, with apical angle of about 85°, or hemispherical; whorl in front of the shoulder ornamented with fine raised revolving threads."
- "Orthaulax caepa is intermediate in shape between 0. inornatus and 0. aguadillensis. Its apex is blunter than that of 0. inornatus but more acute than that of 0. aguadillensis. It differs from both in the ornamentation of spiral threads in front of the shoulder. The cast of the interior appears to be more slender than that of either 0. inornatus or 0. aguadillensis, and the whorls of the cast to be more rounded than those of 0. inornatus but very similar to those of 0. aguadillensis. The callus in 0. caepa is evenly lunate, but that of 0. aguadillensis is asymmetric, the greatest thickness being in front of the shoulder, and is much thicker in proportion to its length than that of 0. caepa; the callus is thin and inconspicuous in 0. inornatus. There are two forms of 0. caepa, a pointed or conical form and a domed or hemispherical form. It is possible that these different shapes may be secondary sexual characteristics."
Locus typicus: Consolacion del Sur, Pinar del Rio, Cuba
Stratum typicum: Oligocene
Types: U.S. Nat. Mus. catalogue No. 166980