Remarks on the Difficulty of Distinguishing Certain Genera of Testaceous mollusca by Their Shells Alone, and on the Anomalies in Regard to Habitation Observed in Certain Species
John Edward Gray. "Remarks on the Difficulty of Distinguishing Certain Genera of Testaceous mollusca by Their Shells Alone, and on the Anomalies in Regard to Habitation Observed in Certain Species." Philosophical Transactions of the Royal Society of London (1835) 301-310