Cerithiopsis io
Cerithiopsis io is a species of sea snail, a gastropod in the family Cerithiopsidae, which is known from the Caribbean Sea and the Gulf of Mexico. It was described by Dall and Paul Bartsch in 1911. Description 
The maximum recorded shell length is 2.3 mm. Habitat 
Minimum recorded depth is 5.4 m. Maximum recorded depth is 6 m.

References

io
Gastropods described in 1911