Shell: small, light, ovate to sub-pyriform, ranging from 18-21 mm.
Spire concealed. Teeth: 16 columellar teeth; 16 labral teeth.
Sculpture: smooth, porcelaneous.
Aperture elongate, narrow, slightly wider at anterior.
Exterior colour blue grey, evenly dusted with fine brown freckles; brown blotch central on the dorsum; base cream; margins cream with diffuse brown spotting; brown terminal spots at each end. Mantle line indistinct .
Specimens
Subspecies: Purpuradusta gracilis macula (Angas, 1867) QLD to NSW. Base and margins pale yellow; pale blue-grey dorsum; minimal banding; large, dark terminal blotches. Myora light, Australia Size: mm Collected: 1989 under coral slabs in an area of mud, silt and sand bottom
Subspecies: Purpuradusta gracilis macula (Angas, 1867) QLD to NSW. Base and margins pale yellow; pale blue-grey dorsum; minimal banding; large, dark terminal blotches. Caloundra [Nth Headland], Australia Size: mm Collected: 1987 found in 2m of water on a rocky reef platform, 4m from shore
Subspecies: Purpuradusta gracilis macula (Angas, 1867) QLD to NSW. Base and margins pale yellow; pale blue-grey dorsum; minimal banding; large, dark terminal blotches. Myora Reef, Australia Size: 21.51mm Collected: Unknown Collected at low tide.
Subspecies: Purpuradusta gracilis macula (Angas, 1867) QLD to NSW. Base and margins pale yellow; pale blue-grey dorsum; minimal banding; large, dark terminal blotches. Spider Bay, Australia Size: 19.85mm Collected: Unknown Collected from under algae covered rocks and coral slabs on slightly silty rock and coral reef at 2-3 m by hand [low tide] at extreme low tide [-0.2m].
Subspecies: Purpuradusta gracilis macula (Angas, 1867) QLD to NSW. Base and margins pale yellow; pale blue-grey dorsum; minimal banding; large, dark terminal blotches. Stanage Bay, Australia Size: 20.89mm Collected: Unknown Collected from under algae covered rocks and coral slabs on slightly silty rock and coral reef at 2-3 m by hand [low tide] at extreme low tide.
Subspecies: Purpuradusta gracilis macula (Angas, 1867) QLD to NSW. Base and margins pale yellow; pale blue-grey dorsum; minimal banding; large, dark terminal blotches. Wreck Beach, Australia Size: 20.58mm Collected: Unknown Collected on Coral and rock reaf at 1-2 m by Snorkle.
Wilson Island, Australia Size: 19.57mm Collected: Unknown No data. Exhibits slight melanism and rostration.
Pumpkin Island, Australia Size: 21.45mm Collected: Unknown No data. Exhibits slight melanism and rostration.
Subspecies: Purpuradusta gracilis macula (Angas, 1867) QLD to NSW. Base and margins pale yellow; pale blue-grey dorsum; minimal banding; large, dark terminal blotches. Minnie Waters, Sth Headland, Australia Size: mm Collected: 1989 found 10m from shore in the early afternoon on rocky reef
forma: hilda This form from Western Australia. More ovate; parse margin spots; without blotches at the terminals; dorsum pale green-grey without bands; dark blotch centrally. Cape Keraudin, Australia Size: 18.05mm Collected: Unknown Collected at low tide.
Ela Beach, Papua New Guinea Size: mm Collected: 1984 found on large algae covered rock at low tide 4m from shore
Balabac Island, Philippines Size: 16.52mm Collected: 2007 Collected from dead coral heads on coral and sand at 25-30 m by scuba diver.
forma: japonica (Schilder, 1931) from Japan; elongate; often large; dorsal banding diffuse and dark; dorsal spotting dense and irregular with compact blotch . Cape Ashizuri, Japan Size: 14.98mm Collected: Unknown No data. This specimen form the northern part of the range.
Subspecies: Purpuradusta gracilis notata (Gill, 1858) Oman to East Africa. Broad; calluses yellowish; dorsum bluish with distinct bands, forming a blotch centrally; yellow band above spire; tips greyish. Gulf of Oman, Oman Size: mm Collected: 1985 No data.
Subspecies: Purpuradusta gracilis notata (Gill, 1858) Oman to East Africa. Broad; calluses yellowish; dorsum bluish with distinct bands, forming a blotch centrally; yellow band above spire; tips greyish. Dorale, Djibouti Size: 17.86mm Collected: Unknown Collected from under coral slabs at 5-7 m by scuba diver.
The Gneerings off Mooloolabah, Australia Size: mm Collected: Collected by diver. Courtesy S Grail.
