Localities.—Dredged North Harbour, the specimen figured 6-5 mm. in length. This specimen is yellowish with a white base, and a white band near the top of the whorl. Pure white specimens were abundant associated with infelix in 6-9 fathoms, Sow and Pigs Reef, and it was also taken alive in 15 fathoms, Jervis Bay. It also occurs with infelix and other species on the outer beaches.
Some confusion has in the past existed as to the exact identity of olivella and infelix. Hedley allowed both species in his check list, but May synonymized infelix with olivella. May previously had synonymized a species of his own, procella, under infelix. After examining long series from several localities, both in our own and the Australian Museum collections, I am satisfied that two forms exist, a narrow and a broad one; the broad form rounded, the narrow with nearly straight sides. The narrow form also has a squarer shoulder at the top of the aperture, a feature more apparent from the back of the shell. From Reeve's original description, and from specimens in the Australian Museum compared with the type, the narrow form'is the true olivella. I think their association together is somewhat accidental, as live specimens of olivella in deeper water are by themselves, while infelix is particularly abundant on the beaches, with olivella only occasionally present.

As Marginella procella May:
Shell elongately oval, yellowish-white, with traces of two yellow bands; spire small, of three whorls, partly covered by a callus, which extends from the columella over half the front of the shell, and also considerably behind the outer lip. This is a rare feature amongst our Marginellas. Columella convex, with three moderate sized, strongly ascending plaits, the first two being close together; there is a fourth retreating plication considerably above the others. Outer lip not much thickened, and strongly incurved; it rises above the level of the spire. The aperture is rather narrow.
Length 5.5 mm Breadth 4.5 mm.
Type, from 24 fathoms, in Storm Bay (whence the name;, 40 fathoms, off Schouten Id., four examples. I also have a specimen from Port Jackson. It resembles M. inconspicua, Reeve, which, however, has a much more exserted spire, and a finely crenated lip.

As Marginella binivitta Laseron:

Shell oval, white and translucent, with two pale yellow bands on the body whorl, which are apt to fade fairly rapidly. Spire very short and small, of two or three whorls. Body whorl rounded with a very slight shoulder. Aperture as long as the shell, of moderate width above but broadening below, its junction almost at the apex, the rounded shoulder level with or even above the apex. Outer margin rounded, with a slight varix, narrowly inflected, the edge plain with no trace of denticulation. Canal of moderate width, rounded. Columella plications four, the lower two well marked and oblique, the third much smaller. The fourth plication is well above the third and is very small, almost obsolete, so that at first sight the shell seems tri-plicate. The four plications are within the lower two-fifths of the aperture. Length, 6*5 mm.
Localities.—Fifteen fathoms, Jervis Bay (type), several specimens from a pure sand bottom; 30-35 fathoms, off Crookhaven, abundant in sandy mud.
This approaches close to M. altilabra May, but has a still higher and more expanded aperture. It is also like the species May records from Tasmania as agapeta Watson, but which has but three plications. Incidentally this is nothing like the original figure of agapeta, the Tasmanian record of which is exceedingly doubtful. The nearest relation, however, is olivella, from which it is distinguished by the very high aperture and more tapering anterior extremity.