Type species: Distorsio pusilla Pease. 1861. Recent. Indo-West Pacific.

DIAGNOSIS. — Teleoconch small (to about 12.5 mm high), tall and narrow for family, with long, narrow aperture. Coiling weakly but obviously excentric. Inner lip without expanded callus over previous whorl. Interior of outer lip with uppermost denticle the most prominent, apart from minute denticle in posterior notch of some specimens. Base of inner lip lacking expanded, hollow nodulous ridge, protruding to right into aperture, of Distorsio, but instead having a much higher-placed row of 4-5 short, well raised, transverse ridges, situated slightly obliquely on outer part of mid-columellar callus. Varices narrow, prominent, present down whole teleoconch. The generic position of Distorsio pusilla has long been in doubt. When proposing Personopsis gen. nov. for the species of Personidae previously placed in the ranellid subgenus Sassia (Personella), I noted that another genus, distinct from Personopsis. "might prove necessary" for D. pusilla. This genus is now provided, because of the combination of several distinctive characters seen in D. pusilla. Distorsomina pusilla differs from all Distorsio species in its much smaller size, in its narrower form, in its narrow aperture, in lacking the expanded columellar shield, and in lacking the very prominent, nodulous basal columellar ridge that is seen in both Distorsio and the New Zealand Late Paleocene personid Kotakaia simplex Beu, 1988 . The prominent, nodulous basal columellar ridge, built out rapidly in Distorsio by leaving a spiral hollow beneath it, is absent in the personid genera Distorsionelta. Distorsomina and Personopsis. but low rows of nodules that appear to be homologous are present in all these genera: a uniform row low on the columellar base in Distorsionelta, a basal columellar row decreasing anteriorly in size in Personopsis (and so more resembling that of Distorsio than in the other genera. but not elevated on a hollow ridge), and a mid-columellar row of relatively large, uniform, short, oblique, transverse ridges in Distorsomina. Varices before the terminal one are very indistinct in Distorsionella, Personopsis and Kotakaia Beu, 1988, but more prominent in Distorsio and Distorsomina. Kotakaia is rendered further distinctive by its very simple sculpture of low. wide, smooth spiral cords, and by having regular coiling and only four extremely prominent, narrow nodules inside the outer lip. Personopsis differs further from Distorsomina by its wide form, with a widely conical spire and wide last whorl, tapering unusually gradually to a short, widely open siphonal canal, by having the flared inner lip shield expanded over the previous whorl, as is also prominent in Distorsio and, again as in Distorsio. by having the second or. In most species, third nodule from the adapical end of the interior of the outer lip markedly enlarged compared with the others. The two new species named below in Personopsis closely resemble the Italian Pliocene type species, P. grasi, and these and records (listed below) of Recent Atlantic specimens closely resembling P. grasi demonstrate that Personopsis remains a distinctive genus in the modern fauna. The small size, narrow shape, and distinctive apertural characters of Distorsomina pusilla demonstrate that it is distinct phylogenetically from Personopsis and deserves its own genus.