This species, together with H. flexicolumella, differs from others on Lord Howe Island in having a columellar bulge and an operculum with a rudimentary peg and no white smear or spot. The shell is sculptured with growth lines only and the suture is simple or weakly channelled. The maximum length of the shell is about 2.9 mm
The penis is simple in all Hemistomia species.
Hemistomia beaumonti Ponder, 1982
Class Gastropoda
Infraclass Caenogastropoda
Order Littorinida
Suborder Rissoidina
Superfamily Truncatelloidea
Family Tateidae
Genus Hemistomia Crosse, 1872
Original name: Hemistomia beaumonti Ponder, 1982. In Ponder, W.F. (1982) Hydrobiidae of Lord Howe Island (Mollusca: Gastropoda: Prosobranchia). Australian Journal of Marine and Freshwater Research 33: 89-159.
Type locality: Southern tributary of southern end of main gully in middle of Mt. Gower, Lord Howe Island.
Found in streams, seepages and pools. It is assumed that like most tateids, the Lord Howe Island Tateidae feed on bacteria, microscopic algae, diatoms and possibly decaying vegetation.
Restricted to the top of Mt Gower, Lord Howe Island.
Ponder, W. F. (1982). Hydrobiidae of Lord Howe Island (Mollusca: Gastropoda: Prosobranchia). Australian Journal of Marine and Freshwater Research 33: 89-159.
