Coluber gramineus Shaw, 1802 or Coluber viridis Bechstein, 1802 (Serpentes, Viperidae, Crotalinae): which one will remain valid?

Two species of Indian pit vipers, Coluber gramineus Shaw, 1802 and Coluber viridis Bechstein, 1802 were described the same year based on the same holotype. Coluber gramineus has subsequently been considered the valid nomen of the Indian species now known as Craspedocephalus gramineus. We here demonstrate that, in fact, Coluber viridis Bechstein, 1802 was published before Coluber gramineus Shaw, 1802 and would have priority if the Principle of Priority was strictly followed. For preserving the stability of the systematics of Asian pit vipers, we take the suitable nomenclatural action to protect the nomen Coluber gramineus Shaw, 1802 (nomen protectum or mnemokyronym) and to render Coluber viridis Bechstein, 1802 a nomen oblitum (lethakyronym). We also discuss the status of Vipera viridis Daudin, 1803, based on the same specimen previously designated as its lectotype (lectonymophoront) and the uses of the species nomen viridis in the literature.