Batillaria minima: As Cerithium minimum Gmelin:
Shell only moderately solid, with low, longitudinal ribs and faint revolving ridges, which cut the longitudinal ribs more or less into nodules. In addition to the revolving ridges there are fine revolving threads in their interstices. The aperture is rather large; the basal canal is turned sharply to the left. Color varying from jet black to ashy, variously banded.
Length, 15; diameter, 6 mm.
This species is quite close in appearance to C. luteosum variabele. It is generally less solid and more glossy than that species and has more distinct longitudinal ribs. Its aperture is generally larger and the basal canal more distinctly turned to the left.

Batillaria minima: Batillaria minima (Gmelin, 1791) West Indian False Cerith
Distribution: Florida, Texas; Brazil; Bermuda. Size: 12 to 18 mm.
Description: Color variable from black to brown to white, often with narrow or broad dark or lighter bands of base color; shape pyramidal; sculpture variable, typically with many spiral ribs and axial ridges; varices absent; aperture with rounded sides; siphonal canal short and twisted to left; operculum round and multispiral. Habitat: Common intertidally in brackish water in mud.
Remarks: Formerly in the family Potamididae. May not be a Texas resident; only one beach-worn specimen in HMNS collection. Other old beach-worn specimens have been collected in Port Isabel. B. minima is often confused with Cerithium lutosum, which differs by having rounded nodules and different-shaped aperture. See Bequaert (1942); Ode (1990c).