Notoacmea flammea (Quoy & Gaimard, 1834)
Description: Shell lightweight, low to medium in height, posterior slope convex, anterior slope slightly concave; widest centrally or posteriorly; apex slightly to markedly in front of centre. External sculpture of about 50-100 microscopic, widely spaced radial threads, sometimes nodulose and occasionally superimposed on broad, low radial folds. External colour variable; background of cream, fawn, dark green or black, with a superimposed pattern of rays or reticulate dots. Interior colouration similarly variable; adult shells with dark spatula, black or brown margin and blue-white zone between; juveniles with external colouration showing through.
Size: Up to 24 mm in length, commonly 10-15 mm.
Distribution: Endemic to Australia: Sydney, NSW, to Perth, WA, including Tasmania.
Habitat: On protected rocky shores in the lower littoral, often on the sides of or under boulders. Uncommon in NSW, common in southern Australia.
Comparison: Readily separated from the other NSW limpets by the microscopic radial threads.
Synonymy: Acmaea scabrilirata Angas, 1865; Acmaea subundulata Angas, 1865; Notoacmea flammea diminuta Iredale, 1924
Remarks: The fine radial threads are seen only with magnification. They are only seen on un-corroded shells, which are a minority of the population.
Fig. 1 Bottle and Glass Rocks, Sydney Harbour, NSW (C.049539)
Fig. 2 a. Sydney Harbour, NSW (C.049539) b. Cape Sorell, Tasmania (C.424258) c. Between Burnie and Stanley, Tasmania (C.090689)
Copyright Des Beechey 2004