492 ON THE DEVELOPMENT OF CHLOËON (EPHEMERA) DIMIDIATUM. 
DESCRIPTION OF THE PLATES. 
PLATE LVIII. 
. 1. Basal part of one of the caudal processes, showing the mode of reproduction, x 60. 
. 2. Basal portion of the antenna in the 20th state, showing, within, that of the 
proimago, x 60. 
Fig. 3. Portion of the above, x 250. 
Fig. 4. Upper lip of full-grown larva, x 60. 
Fig. 5. Mandible, x 60. 
Fig. 6. Processes of ditto, x 250. 
Fig. 7. Maxilla, x 60, 
Fig. 8. Labium, x 60. 
Fig. 9. Tongue?, x 60. 
Fig. 10. Egg-tube, x 250. 
Fig. 11. Portion of abdominal process, x 250. 
PLATE LIX. 
. 12. Fore leg of proimago, x 30. 
. 13. Margin of wing of ditto, x 250. 
. 14. Posterior segment of the abdomen in the male, seen from below, x 60. 
. 15. Head of imago, x 30. 
. 16. Fore leg of imago, x 30. 
. 17. Hind leg of ditto, x 30. 
+ 18. Margin of wing of imago, x 250. 
. 19. Chloé (Diptera) : proimago, female, after Pictet, about half the natural size. 
. 20. Chloé (Diptera) : imago, female, 
: 21. Chloé (Diptera) : imago, male. 
