10 THOMAS SAY FOUNDATION 
roe 
ee Antenna 
S A Segooes Maxillary palpus 
og 
yen ~$0 ---------- Labial palpus 
Opt gO ee Labrum 
<i jan eee eee Clypeus 
> _ _.Ocellus 
f7—_ Lateral tubercle 
—--Compound eye 
_.~Occipital ridge 
RN —— Occiput 
__.Pronotal disc 
+. --- Flange 
——-~Marginal groove 
: A\\ 
cy ry 
., ¢Pronot 
ths te! Tt Fe 
Pak ae 5 Gill tuft 
MS ee RAR ae Ra Se Eye alee Trochanter 
: Metathorax - 
= milastester atlas oe fag Cap slg. wl. hl eR ae A es Wing case 
ee easels ee ee Femur 
Tibia 
ll. 
- Hair fringe 
re-- - ABDOMEN ~--- 
Fig. 1. A generalized stonefly nymph showing the main structural parts used 
in the descriptions and keys of the various species. 
