344 THOMAS SAY FOUNDATION 



PLATE 27. 



Genitalia of Isoperla. 



Fig. 1. Isoperla marmona Bks. $ , dorsal view. 



Fig. 2. Isoperla marmona Bks. $ , ventral view. 



Fig. 3. Isoperla marmona Bks. $ , ventral view. 



Fig. 4. Isoperla signata Bks. $ , dorsal view. 



Fig. 5. Isoperla signata Bks. $ , ventral view. 



Fig. 6. Isoperla signata Bks. $ , ventral view. 



Fig. 7. Isoperla minuta Bks. $ , dorsal view. 



Fig. 8. Isoperla minuta Bks. $ , ventral view. 



Fig. 9. Isoperla minuta Bks. 9 , ventral view. 



Fig. 10. Isoperla montana $, dorsal view. 



Fig. 11. Isoperla montana $ , ventral view. 



Fig. 12. Isoperla montana $>> ventral view. 



Fig. 13. Isoperla sordida Bks. $ , dorsal view. 



Fig. 14. Isoperla sordida Bks. $ , ventral view. 



Fig. 15. Jsopcrla sordida Bks. $ , ventral view. 



