Bxplanation of Plate 1. 



3iinQlmir) Society 

 Fig. 



1. Two imagos of Hydropsyche sp. ?, at rest, natural size. 



2. Imago of Hydropsyche sp. ?, lateral view, x6. 



3. Larva of Hydropsyche sp. ?, lateral view, x 3}'2. 



4. Pupal case of Hydropsyche sp. ?, x 2. 



5. Imago of Roederiodes juncta, lateral view, x 10. 



6. Larva of Roederiodes juncta, lateral view, x 5. 



7. Pupa of Roederiodes juncta, lateral view, x 5. 



8. Pupa of Roederiodes juncta in an habitual position in the abandoned pupal 



case of Simulium venustum. 



9. Egg masses of S. venustum, and two females ovipositing. 



10. Pupae, empty pupa skins, and pupal cases of S. venustum. 



11. Larva of S. venustum, x 5. 



12. Male imago of Leuctra tenella, dorsal view, x 4. 



13. Imago of Baetis pygmaea, lateral view, x 5. 



14. Imago of Baetis pygmaea, dorsal view, x 5. 



15. Imago of Heptagenia pulchella, x 2. 



16. Nymph of Heptagenia pulchella, natural size. 



17. Pupal cases of Hydropsyche sp. ?, in situ, natural size. 



18. Pupae of Simulium venustum, in situ. 



19. 20. Larva of S. venustum in situ. 



500 



