This species has a simple columella and an operculum with 4-8 short teeth on a white smear. The shell is sculptured with growth lines only and the suture impressed. Its maximum length is about 4.2 mm.
The penis is simple in all Hemistomia species.
Hemistomia pusillior (Iredale, 1944)
Class Gastropoda
Infraclass Caenogastropoda
Order Littorinida
Suborder Rissoidina
Superfamily Truncatelloidea
Family Tateidae
Genus Hemistomia Crosse, 1872
Original name: Fluviorissoina pusillior Iredale, 1944. In Iredale, T. (1944) The land Mollusca of Lord Howe Island. Australian Zoologist 10: 299-334.
Type locality: 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 summit of Mt, Gower, Lord Howe Island.
All the Hemistomia species are strongly clustered into distinct geographical locations on Lord Howe Island.
Iredale, T. (1944). The land Mollusca of Lord Howe Island. Australian Zoologist 10: 299-334, pls 17-20.
Ponder, W. F. (1982). Hydrobiidae of Lord Howe Island (Mollusca: Gastropoda: Prosobranchia). Australian Journal of Marine and Freshwater Research 33: 89-159.
