Shells minute, subcylindrical, arched, operculum horny. Sculpture of concentric growth marks.« The family […] is subdivided into three subfamilies, herein listed. 1) Subfamily Caecinae Gray, 1850: larval shell planispirally coiled, discarded when the mollusc has built a new portion of tube and sealed the posterior end with a septum; 2) Subfamily Pedumicrinae Iredale & Laseron, 1957: larval shell uncoiled, kept attached to teleoconch all through the life-time. 3) Subfamily Strebloceratinae Bandel, 1996: larval shell trochospirally coiled, kept attached to teleoconch all through the life-time. » – Pizzini, Raines & Vannozzi: “The family Caecidae in the South-West Pacific (Gastropoda: Rissooidea)”, Bollettino Malacologico vol.49 suppl.10, Milano 2013, p.1.
 

Apex subspiral. In adult specimens, after the losing of the latter, the area is closed by a calcareous septum.
 

« The genus Parastrophia contains shells whose protoconch remains attached to the teleoconch, unlike the genus Caecum. They have a coiled protoconch followed by an uncoiled stage forming a more or less twisted tube. The teleoconch is almost always separated from the uncoiled protoconch by a ring-like varix. ” – Pizzini, Raines & Vannozzi: op. cit. p.43.