Carapace subquadrate, up to 0.8 mm. Surface strongly reticulate with scattered stout, castellate/multifurcate, conjunctive spines; conspicuous spines present posterodorsally, on subcentral tubercle, and anteroventrally of the subcentral tubercle. Anterior marginal area with somewhat clavate spines arranged in two concentric rows, one marginal and the other on a submarginal rim. Posteroventrally is a broad, non-reticulate rim bearing several large clavate spines. Distal process of male copulatory appendage subtriangular with a rounded distal corner (A. dunelmensis 3 ).
Sublittoral, recorded between depths of 50-100 metres.
NE England, Scotland, Norway and E Greenland.