Cheirocratus pseudosundevallii (Amphipoda, Cheirocratidae), a new species from Arcachon Bay, Bay of Biscay.

An examination of some benthic amphipods belonging to the genus Cheirocratus from Arcachon Bay revealed that they exhibited a combination of morphological character states that distinguished them from all previously described Cheirocratus species. In the form of the gnathopods, Cheirocratus pseudosundevallii is very close to two other European species: C. sundevallii and C. intermedius. An actualized key to the species of Cheirocratus is provided. [ABSTRACT FROM AUTHOR]