Note 118 — 5. Genus—PYRGOMA.
Reading edition
It is quite possible that this may be the Balanus duploconus of Lamarck, but with such a character as the following, who can recognise a species? “B. testæ parte supremâ univalvi, indivisâ, convexâ: inferiore turbinatâ, non clausâ: aperturâ ellipticâ. L’exemplaire est sans opercule et incomplet.”