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Helisoma dispar Blueford, 1982

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Two shells, 84-120 and 36µm in diameter. Outer surface thorny with varying number of prominent bladed spines (3-40), 24-48µm in length. Spines sometimes along polar axis, outer shell becoming slightly elongated. Pores rosette-shaped, of equal size, diameters 10-18µm, closely packed, 11-20µm between pore centers. Inner pores circular, of equal size, 5µm in diameter, closely packed, 10-15 radial beams connecting inner to outer shell.
Distinguishing features: Two shells with outer surface thorny and varying number of prominent bladed spines. Pores characteristically rosette-shaped. Differs from Helisoma alveolatum (Campbell and Clark 1944) by its rosette-shaped pores and larger outer shell and smaller inner one, and from Helisoma hastatum (Haeckel 1887) by its regularity and type of pores.

note by D. Lazarus 12 May 2005 - Blueford does not explicitly give sources for her generic names but refers in her text to other species in Helisoma including Helisoma hastatum Haeckel 1887. There is no such genus in Hkl, but there is Heliosoma hastatum. Thus Helisoma dispar is probably an original mispelling and should be formally changed to Heliosoma.
Blueford 1982











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