Argalista fluctuata is a species of small sea snail with calcareous opercula, a marine gastropod mollusk in the family Colloniidae.

[1] The small, rather solid shell is spirally striated.

Its colour is yellowish white or pale brownish with irregular waved longitudinal bands of brown, which are rather indistinct.

They are rounded and distinctly and closely spirally grooved.

[2] This marine species is endemic to New Zealand.