A Key to the Nymphs of the British Species of Ephemeroptera with Notes on Their Ecology

abdominal segments abdominal terga adults AMBLESIDE Ameletus inopinatus atrebatinus Baëtis rhodani Berkshire bristles BRITISH SPECIES broad fig buceratus Caenis Caenis horaria Centroptilum luteolum cincta Cloëon dipterum cockade-like scales common and abundant danica dark band dark rings diapause distal East Stoke eggs emergence Ephemera Ephemera danica Ephemerella ignita Ephemeroptera femur FERRY HOUSE fore femora fig fore margin FRESHWATER Full-grown nymphs gills Habrophlebia fusca hairs hatching Heptagenia lateralis instars labial palp labium Lake District lamellae last segment legs length Leptophlebia vespertina long including cerci macrura mandible margin fig maxilla Maxillary palp mesonotum middle moesta muticus pumilus niger overwinter pairs of gills Paraglossae Paraleptophlebia submarginata pennulatum plate PLECOPTERA Pleskot Procloëon pseudorufulum pronotum prothorax recorded Rhithrogena semicolorata Scale lines scambus segment of labial sides of abdominal small nymphs specimens sulphurea summer T. T. Macan tails tapering tenax tergites tergum tibia tiny nymphs tumida venosus vernus Windermere winter