Carapace large about 1.3 mm long; dorsal margin broadly but unevenly arched, anterior margin evenly rounded, posterior margin acutely tapered, ventral margin gently sinuous with concavity at about mid-length. Narrowly lanceolate in dorsal view. Greatest height and width one-third length from the anterior end. Colour in living specimens generally pale yellow widh a red/ brown ventral area.
It has been recorded alive from the littoral to around 70 metres depth; Sars recorded this species as burrowing in soft mud.
Males are unknown. This species may be distinguished from other superficially similar British species by its muscle scar pattern and distinctive branching marginal pore canals. Species of Pontocypris, Propontocypris and Macrocypris are similar in shape, but all have simple marginal pore canals and also differ in muscle scar patterns and details of the appendages.
S Norway, the Skagerrak, N and SW Britain.