Distribution: Texas; Yucatan; Cuba.
Size: 0.5 to 0.75 mm (500 to 740 µm).
Description: Color translucent white; shape planorbid; highly sculptured with continuous sigmoid radial ribs that extend from apex to umbilicus on first postnuclear whorl, and from upper suture to umbilical wall on body whorl; microscopic spiral lines cross over surface of shell; spiral ridge below suture is separated by a narrow channel, producing carinae on both sides of shell; crossed by numerous axial riblets, producing small nodules; nuclear whorl smoothish with a spiral rib on about last half of nuclear whorl; aperture unique as it is folded upward on top and downward on bottom next to columella, narrows away from columella; umbilicus wide. Habitat: Calcareous environments. Previously recorded depth range 8 to 15 m (26 to 50 ft).
Remarks: Specimen in photograph from the FGB. Specimens collected from depths from 21 to 51 m (70 to 168 ft). One of Texas' smallest gastropods and typically overlooked in benthic research. The genus Orbitestella has worldwide distribution, but most known orbitestellids are found in the southern hemisphere. First record for Texas. See Ponder (1990); Rolan and Rubio (1992); Moolenbeek (1994); Barrera (2001); Simone and Zelaya (2004). Synonyms: O. cubana Rolan and Rubio, 1992; O. similis Rolan and Rubio, 1992.