Abstract

Richardsonobdella, gen, nov., is characterised externally by well developed suckers, one pair of eyes, 12-annulate mid-body segments and smooth skin. Internal characters include five pairs of testisacs, small atrial-bursa complex, vector tissue with paired strands that fuse with ovisacs, fused posterior crop caeca with fenestrae, and spacious coelomic system with segmental connections among dorsal, ventral and lateral sinuses, and among testicular, dorsal and lateral sinuses, but lacking pulsatile vesicles. Richardsonobdella lineatae, sp. nov., is characterised by 21 black transverse pigment bands separated by narrow unpigmented regions. Suckers are also black; oral with two transverse unpigmented bands, caudal with 13 unpigmented radial lines. Maximum length, including suckers, is 12 mm.