Mazatlania hesperia: The shell is similar to M. acicuhta (Lam.) of the "West Indies, but has spiral striation throughout the last three or four whorls, stronger at the base, and the siphonal fasciole is bounded by a sharp, dark brown ridge. The axial ribs (9 to 12 on last whorl) are somewhat prominent at the periphery but not tuberculate, and gradually diminish to the suture, without constriction around the upper part. Axis pervious, viewed from the base. Color, faint buff with a dull, livid brown band (sometimes interrupted) between periphery and suture, followed by a zone without markings, the basal slope with more or less interrupted zigzag lines of cinnamon-rufous or chestnut brown, the carina bounding the siphonal fasciole chestnut brown.
Length 15.3 mm., diam. 5 mm.; 9 whorls.