[German version]

Longest river (1,000 km) of the Persian core provinces  Arachosia and  Drangiana (modern Helmand Rūd), now inside Afghanistan. Today the Helmand no longer reaches the lake basin of Daryāče-ye Sı̄stān, but disappears in swamps because some of its water is diverted for irrigation. Arr. Anab. 4,6,6 reports that this river flows through the territory of the Εὐεργέται (Euergétai,  Ariaspae). Plin. HN 6,92 calls the river the Erymandus. Curt. 8,9,10 erroneously located the river in India with the name Ethymantus.

Treidler, Hans (Berlin)