Belongs within: Heterobranchia. The Siphonarioidea are a group of gastropods uniting the living Siphonariidae with the tentatively assigned fossil Acroreia. The Siphonariidae, false limpets, are a group of air-breathing limpet-like gastropods found in marine and brackish waters. A lateral pneumostome is present, its position marked by an inner groove on the shell and an interruption… Continue reading Siphonarioidea