Type species, designated by Nevill (1884, p. 83), Rissoina pulchra C. B. Adams. Morch's diagnosis of Phosinella as a subgenus reads: "T. reticulata, apertura profunde sinuata, opercula apophysi, styliforme, postice denticulis". This very wide definition, if literally applied, will cover all of the very great number of clathrate species living in the Atlantic, Pacific, and Indian Oceans. Some differentiation is undoubtedly necessary to simplify the classification. Before the introduction of Phosinella, Schmeltz (1874) had in fact proposed Isselia for clathrate species with peculiar apertures simulating an anterior canal. Iredale (1955) proposed Phintorene for small Australian tropical species approximating closely to the true Phosinella. Still another group of Australian species can be recognized. These are short, broad species, of few whorls, with peculiar planoid protoconchs, and for these Planapexia is later proposed.
The type of Phosinella comes from the West Indies, and is a large shell, one of its features being the strong basal fold and the very deep, anteriorly placed columella sinus. To discriminate between this and the other 3 clathrate genera the principal characters may be summarized as follows:
Phosinella.—Over 8 mm in length, mature whorls 7 or over.
Phintorene.—Under 6 mm in length, mature whorls under 7.
Planapexia.—Mature whorls 4-6, apices blunt.
Isselia.—Aperture with pseudo-canal.

Genus Phosinella Moerch, 1876
Type species: Phosinella pulchra (C. B. Adams, 1850)
Diagnosis: Shell having strong reticulate sculpture with axials and spirals of nearly equal strength.