Electroma georgiana: "Butterfly Shells." Moderately convex, transparent, smooth, thin; varying in colour, pillucid white, or shades of brown or green, with or without coloured rays of spots. Length 40 mm., height 26 mm., section 12 mm. Type locality: King George Sound.
LOG. : Very genera] and rather common, all around the South Australian coast and westward to Fremantle, beach and dredged to 104 fathoms. S.W.A., S.A., Tas., Vict,, N.S.W.
Remarks: A variable featureless species, but attractive withal. The shells are very light in weight, and the spray often deposits them a little above the regular high tide mark.

Electroma virens: Obliquely ovate, slightly sinuated posteriorly, horny, rather stout, smooth; bright olive-green, rayed throughout with minute opaque white dots. Length 17 mm., height 17 mm., section 7.5 mm. Type locality: Gulf St. Vincent.
Loc.: Not common, Port Willunga, Royston Head, Fowler Bay; King Island. S.W.A., S.A., Tas., Vict. Remarks: Slightly more globose than E. georgiana. Approaching Pterelectroma Iredale 1939.