Species Account

Isognomon bicolor (Adams, 1845)

Pterioidea : Pteriidae

Tebble name: n/a
Smith & Heppell name: n/a

To size: To 35 mm. Shell Structure: Robust valves, flaky, fragile at ventral margin. Equivalve: Slightly inequivalve. Equilateral: Inequilateral. Tumidity: Compressed. Outline: Irregular oblique ov.

Sculpture: Smooth or with flaky commarginal lamellae. Margin: Irregular but smooth margin. Ligament: Multiple set in grooves along straight dorsal margin. Hinge: Hinge edentulous. Pallial Musculature: One large adductor large muscle. Colour: White with purple tinge, may be brown to purple brown. Internal nacreous.

Distribution & Ecology

From Florida to Brazil.

4 specimens attached to plastic spool, Chesil Beach, Dorset.

Depth Range
Continental Shelf (to 200m)

Additional Information & Related Species

Related Species


Listed are literature citing Isognomon bicolor (Adams, 1845). Reference containing the species Type Description is highlighted.

Adams C.B. 1845. Specierum novarum conchyliorum, in Jamaica repertorum, synopsis.. Proceedings of the Boston Society of Natural History. 2: 1-17.
Holmes A.M., Oliver P.G., Trewhella S, Hill R. & Quigley D.T.G. 2015. Trans-Atlantic rafting of inshore mollusca on macro-litter. American molluscs on British and Irish shores, new records.. Journal of Conchology . 42 (1): 41-49.


  • Conchological Society of Great Britain & Ireland
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    Check List of European Marine Mollusca
  • MarLIN
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  • NBN Gateway
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  • BivAToL
  • MarBEF
  • Malacological Society
  • Unitas Malacologica
  • Census of Marine Life
  • MarBEF
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Record last modified: 13/05/2016