Caecidae

Caecidae is a taxonomic family of minute sea snails or micromolluscs, marine gastropod molluscs in the order Littorinimorpha.

Habitat
These minute tubular shells can be found living in marine sediment, or among algae or sponges, in warm and temperate seas.

Shell description
The shells in this family are unusual in that the adult shell is a curving tube. In the subfamily Caecinae the protoconch is lost, and the tube is sealed with a permanent calcareous plug at one end. In the subfamilies Ctiloceratinae and Strebloceratinae the protoconch is retained. At the other end, the tube is sealed by a circular operculum. The spiral part is almost always lost when outgrowing the juvenile stage. The color of the shell is white to pale yellow.

Taxonomy
This family contains three subfamilies:
 * Caecinae Gray, 1850
 * Ctiloceratinae Iredale & Laseron, 1957
 * Strebloceratinae Bandel, 1996

Genera

 * Caecum Fleming, 1813
 * Carinocera Iredale & Laseron, 1957
 * Ctiloceras R. B. Watson, 1886
 * Elephantanellum Bartsch, 1920
 * Elephantulum Carpenter, 1856
 * Enigmerces Iredale & Laseron, 1957
 * Fartulum Carpenter, 1857
 * Gladioceras Iredale & Laseron, 1957
 *  Jayella Iredale & Laseron, 1957
 * Mauroceras Vannozzi, 2019
 * Meioceras Carpenter, 1859
 * Parastrophia de Folin, 1870
 * Ponderoceras Bandel, 1996
 * Pseudoparastrophia
 * Strebloceras Carpenter 1859
 * Torresella Iredale & Laseron, 1957
 * Transcopia Iredale & Laseron, 1957
 * Watsonia de Folin, 1880 (possibly synonymous with Parastrophia)
 * Genera brought into synonymy :
 * Brochina Gray, 1857 : synonym of Caecum Fleming, 1813
 * Brochus T. Brown, 1827 : synonym of Caecum Fleming, 1813
 * Micranellum Bartsch 1900 : synonym of Caecum Fleming, 1813
 * Moreletia de Folin, 1869 : synonym of Parastrophia de Folin, 1869
 * Odontidium Philippi, 1836 : synonym of Caecum Fleming, 1813
 * Pedumicra Iredale & Laseron, 1957 : synonym of Parastrophia de Folin, 1869
 * Phleboceras de Folin, 1868 : synonym of Strebloceras Carpenter, 1859
 * Pictocaecum Habe 1978 : synonym of Caecum Fleming, 1813
 * Spirolidium O. G. Costa, 1861 : synonym of Parastrophia de Folin, 1869 : synonym