MAY FLIES AND MIDGES OP NEW YORK 317 



4 Ventral view of nymph of Rhithrogena elegantula Etn. ? 



5 Dorsal view of the same 



6 Ventral view of Iron sp? from Coy Glen near Ithaca 



7 Dorsal view of the same 



PLATE 8 

 Choroterpes and Ameletus 



1 Wings of imago of Choroterpes basalis Banks 



2 Abdominal appendages of the male imago of same, from below 



3 Labium of nymph of the same 



4 Maxilla of nymph of the same 



5 Labrurn of nymph of the same 



6 Mandible of the nymph of the same 



7 Gill filament of the first abdominal segment of the same 



8 Gill lamellae of the fourth abdominal segment of the same 



9 Venation of the wings of Ameletus ludens sp. nov. 



PLATE 9 

 Mayfly nymphs (photographed from alcoholic specimens) 



1 Three nymphs of Ephemerella excrucians Walsh, showing 



differences in depth of coloration ; the left front foot of the left hand 

 'specimen has been lost and is regenerating 



2 Nymph an unknown Ephemerella from Pecos New Mex. 



3 Dorsal and ventral views of nymphs of Heptagenia interpunc- 



tata Say 



4 Dorsal and ventral views of nymphs of Heptagenia sp? no. 3, 



from Ithaca N. Y. 



PLATE 10 



Drunella and Ephemerella 



1 Venation of fore wing of nymph of Drunella grandis Etn. ? 



2 Venation of hind wing of same 



3 Face of the nymph of same (male) 



4 Claw of hind tarsus of same 



5 Claw of hind tarsus of Ephemerella bispina sp. nov. 



G Lateral view of nymph of Drunella grandis Etn?, legs removed 



7 Dorsal view of abdomen of nymph of Ephemerella sp? from 



Richfield Springs N. Y. 



8 Male abdominal appendages of Ephemerella excrucians 



Walsh 



9 Male abdominal appendages of Ephemerella sp? from Pecos N. 



Mex. 

 10 Male abdominal appendages of Ephemerella bispina sp. nov. 



PLATE 11 

 Leptophlebia and Caenis 



1 Venation of wings of Leptophlebia praepedita Etn. 



2 Abdominal appendages of male of same, drawn from mounted slide, the 



ventral processes of the inner appendages somewhat turned aside by 

 pressure of the coverglass 



3 Venation of the wing of Caenis hilaris Say 



4 Venation of the Wing of Caenis diminuta Walker 



