CONTENTS Introduction................... 4 Polyorthini Obraztsov................ 6 Key to the genera of Polyorthini............. 10 Polyortha Dognin................. 11 Notes on species of Polyortha Dognin in the collection of the British Museum (Natural History)................ 13 Lophoprora Meyrick................ 18 L. cyanostacta Meyrick ♂ ♀............. 19 Lopharcha Diakonoff................ 21 Species group 1................. 23 L. quinquestriata Diakonoff ♂♀........... 23 L. chalcophanes (Meyrick) ♀............ 25 L. chionea spec. nov. ♀.............. 30 L. halidora (Meyrick) ♂♀............. 31 L. deliqua spec. nov. ♀.............. 33 L. herbaecolor (Diakonoff) ♂♀............ 36 L. angustior (Diakonoff) ♀............. 38 L. rapax (Meyrick) ♂♀.............. 38 L. orthioterma (Diakonoff) ♀............ 40 L. erioptila (Meyrick) ♂ ♀............. 43 L. cryptacantha spec. nov. ♂♀............ 45 L. maurognoma spec. nov. ♂............. 49 L. siderota (Meyrick) ♀.............. 50 Species group 2................. 50