Cancer

Diagnosis. Male. First antennae unsegmented or partially multi-articulated with incomplete rings. Second antennae basal antennomere variously ornamented but lacking a digitiform process; distal antennomere as in the family but in a few cases (B. achalensis César, 1985; B. paludosa (Müller, 1788); B. papillata Rogers, De los Ríos & Zúñiga) with a basal branching (Linder 1941; Cohen 2012). Mouthparts as in the family. Rigid basal portion of gonopods each bearing a medial spine-like projection; eversible portion of gonopods elongate, usually reaching the first abdominal segment. Genital segments prominent or not in lateral view. Vas deferens not describing a loop. Usually with sexual dimorphism in thoracopods, mainly in the shape and setose armature of endopodites (shape and number of setae). Female. First antennae as in the male. Second antennae as in the family, sometimes with an additional medial bulge or protuberance with setae or spinulae, rarely with a stout spine or medial projection, which together with the apical projection seem to form a cheliform appendage (B. achalensis; B. iheringi Lilljeborg, 1889; B. cornigera Lynch, 1958; B. hiberna Rogers & Fugate, 2001) (Lynch 1958; Cohen 1987; 1995; Rogers & Fugate 2001). Mouthparts as in the family. Thoracopods with sexual dimorphism.