Only two species of Corixidae, commonly known as water boatmen, are known to occur in both the Old and New Worlds. One of these is Callicorixa producta Reuter, which Hungerford (1948) has divided into three subspecies. On the basis of existing records the typical subspecies is restricted to the Scandinavian peninsula and Finland. The second subspecies, producta sackalinensis (Matsumura), is so far known only from northern Manchuria and Sakhalin Island. The third subspecies, producta noorvikensis Hungerford, appears to straddle the Rering Sea, specimens being recorded from near Kolyma River in Siberia and from Bering Island in the Komandorskies east across Alaska and Northwest Territories to Hudson Bay.