The small hermit crabs of the genus Clibanarius are mainly found in tropical regions but one of them, C. erythropus (Latrielle), is common along Mediterranean shores (Holthuis & Gottlieb, 1958); this species was formerly known as C. misanthropus (Risso), but the name C. erythropus has priority (Forest, 1958) and is now in general use. Outside the Mediterranean the species ranges from Brittany to southern Morocco and the Azores (Holthuis & Gottlieb, 1958; Zariquiey Alvarez, 1968). In 1955–7 the extreme northern limit in Brittany was placed at Melon, between Brest and Trémazan (Crisp & Fischer-Piette, 1959); these workers, and also Carlisle & Tregenza (1961), were apparently unaware that the crab had been discovered at Roscoff, on the north coast of Brittany in 1955 (Rullier, 1959; Thiriot, 1965; Bourdon, 1965).