TY - JOUR T1 - On the phylogenetic significance of sagittocysts and copulatory organs in acoel turbellarians. JF - Hydrobiologia Y1 - 1991 A1 - Mamkaev,YuV A1 - Kostenko,AG SP - 307 EP - 314 KW - Simsagittifera KW - Symsagittifera VL - 227 ER -