Systematic notes on Asian birds. 15. Nomenclatural issues concerning the common sand martin Riparia riparia (Linnaeus, 1758) and the pale sand martin R. diluta (Sharpe & Wyatt, 1893), with a new synonymy

A female of Riparia diluta in the ZISP collection and collected by Severtsov, which has sometimes been supposed to belong to the type series, is found to be this species but not the same subspecies and only a topotype. We designate a lectotype for R. diluta as Severtsov’s material was composite. Names introduced by Zarudny (1916) are evaluated and the synonymy of these two species is corrected to take into account the findings of both Zarudny and later workers.