Vallisiopsis contorta n.g. and n.sp. and Gastrocotyle indica n.sp., monogenetic trematodes from marine fishes of the Madras coast

Abstract

Two new monogenetic trematodes of the sub-order Polyopisthocotylea Odhner were obtained from the gills of marine fishes. The characters of the first (Vallisiopsis contorta) agree with those of the subfamily Vallisiinae Price (family Discocotylidae Price) except in the presence of accessory sclerites in the clamp skeleton. As the mere presence of accessory sclerites does not justify the creation of a new subfamily, I refer this species to the subfamily Vallisiinae the diagnosis of which should, however, include the presence of accessory sclerites as an additional character. The second species described belongs to the subfamily Gastrocotylinae Sproston (family Microcotylidae Taschenberg).