AQUATIC INSECTS IN THE ADIRONDACKS 593 



PLATE 16 



Hexagenia variabilis Eaton 



Fig. 



1 Female imago, natural size. Photo from life by J. G. Needham 



2 Dorsal view of the head of the nymph 



3, o^Fore and 'f'hiud feet of the nymph ; /femur; *tibia 



PLATE 17 



Dragonflies 



Fig. 

 lAeschna eonstricta Say 

 2 Gomphus scudderi Selys 



Natural size: photos from life by J. G. Needham 



PLATE 18 



Dragonfly nymphs: photos by J. G. Needham 

 Fig. 



1 Dromogomphus spinosus Selys 



2 Gomphus scudderi Selys 



3 G. brevis Selys 



4 G. spicatus Selys 



5 Ophio gomphus aspersus Morse 

 6Lanthus parvulus Selys 



7 Hagenius brevistylus Selys 

 SDidymops transversa Say 

 Fig. 1 to 7 are from cast skins. 



PLATE 19 



Eggs of nine genera of dragonflies (Odonata-Anisoptera) 

 Fig. 



1 Egg of An ax Junius Dru: the line k-k indicates the depth of its inser- 



tion into cat-tail (T y p"h a ) stems. 



2 Egg of Hagenius brevistylus Selys 



3 Egg of Gomphus descriptus Banks var. borealis Ndm. 



4 Egg of Cordulia Shurtleffi Scudd. 



5 Egg of Plathemis lydia 



6 Egg of Leucorhinia glacialis Hagen 



7 Egg of Celithemis eponina Dru. 



8 Egg of Perithemis domitia Dru. 



9 Egg of Tramea lace rata Hagen 



Gelatinous envelops (g) are indicated for all the figures except 1 and 8: 

 all are magnified about 50 dianaeters. 



PLATE 20 



Gomphinae 



Fig. 

 1-4 Occiput of the female of Ophiogomphus carolus Ndm., seen 



from the front, showing variations in occipital spines 

 5 Genital hamules of 0. johannus Ndm., from the left side, inverted 



