PLATE XXV. 



Fig. io. Ommatidia from the small facetted pigmented area of male Bibio 



eye, X 9°o- 

 Fig. ii. Head of male Bibio hirtus. 

 Figs. 12 to 14. Eye of Anax Junius, Drury. 

 Fig. 12. Cross section of a single eye of adult, X 4 T - 



Fig. 13. A. Two ommatidia from the upper largest facetted part of the eye, 

 X102. 



B. Cross-section of the retinula through the nuclei. 



C. Cross-section of cone and surrounding secondary pigment cells 



and lumina. 



D. Cross-section of cone tip showing surrounding primary or chief 



pigment cells and secondary pigment cells. 



E. Cross-section of three retinula? and enclosed lumina. 



Fig. 14. Two ommatidia from the smallest facetted part of the eye, X I02 - 

 Fig. 15. Eye of Blepharocera capitata Loew. 



A. Two ommatidia from the large facetted division of the eye (dor- 



sal), X 205. 



B. Cross-section through tip of cone showing four cone cells with 



their nuclei and the surrounding secondary pigment cells. 



C. Cross-section of a retinula showing the rhabdomeres. 

 Fig. 16. Adult eye of a male Callibcetis hageni Etn. 



A. Two entire ommatidial elements from the turban or dorsal eye 



and parts of two proximal retinulse whose corresponding cone 

 elements are not shown, X 385- 



B, C, D, and E. Cross-sections of corresponding parts of Fig. A as 



indicated by the lines. 



48 2 



