Perezia helminthorum sp.nov., a microsporidian hyperparasite of trematode larvae from Malaysian snails

Abstract
Amongst parasitic platyhelminthes three Microsporidia are named from cestodes and seven from trematodes. Those in cestodes are Nosema helminthorum Moniez, 1887, Glugea ghigii Guyenot & Naville, 1924 (= Nosema (Plistophora) ghigii Guyenot, Naville & Ponse, 1925) and Stempellia moniezi Jones, 1942. Those in trematodes are Nosema distomi Lutz & Spendore, 1908, Nosema legeri Dollfus, 1912, Nosema echinostomi Brumpt, 1922, Nosema (Plistophora) spelotremae Guyenot, Naville & Ponse, 1925, Glugea encyclometrae Guyenot & Naville, 1924 (= Nosema (Plistophora) encyclometrae Guyenot, Naville & Ponse, 1925), Glugea ghigii Guyenot, Naville & Ponse, 1924 (= Nosema (Plistophora) ghigii Guyenot, Naville & Ponse, 1925) and Nosema dollfusi Sprague, 1964. Other species are recorded but not named.