Theodoxus syriacus (Bourguignat, 1852). A–D. Specimen collected at Sultanköyü, Mardin, Turkey (UGSB 24182); E–H. Specimen from the Yanarsu Stream, Alıçlı, Turkey (UGSB 20518). I–L. Specimen collected near Başdeğirmen, Diyarbakır, Turkey (UGSB 24183); M–O; P–R. Two specimens collected by Bourguignat from İskenderun, Turkey (MHNG-MOLL-111712). All UGSB specimens incorporated into the phylogeny (Fig. 2). Scale bars: 1 mm.