83 

 Day: Ephemeroptera 



f 



9 



Fig, 3:2. o. Wings of Siphlonurus beren/ce illustrating Needham system of wing venation 

 notation; b, wings of Ephemeridae; c, wings of Heptageni idae; d, wings of Baetidae; e, Epheme- 

 ridae, nymph; f, Heptageniidae, nymph; g, Baetidae, nymph (a, Needham, Traver and Hsu, 1935; 

 b-d, adapted from Spieth, 1933; e-g. Murphy, 1922). 



Nymphs 



1. Gills present on segments 1-6 only, rudimentary on 1, 

 operculate on 2, so that gills on 3-6 are under opercula; 



mandibular tusk absent Neoephemera McDunnough 



— Gills present on segments 1-7, rudimentary on 1; mandi- 

 bular tusk present 2 



2. Gills lateral in position, outspread at sides of abdomen; 

 fore tibiae long and slender, not flattened and widened 



P otamanthus Pictet 



— Gills dorsal in position, curving up over abdomen; 

 fore tibiae more or less flattened and widened (burrow- 

 ing form) 3 



