1916] Life History of Pterodontia 321 



5 Gerstacker, A. 1S56. Beitrag zur Kenntniss der Henopier, Stett. Ent. Zeit., 



17: 339-361. ^ -^ , , , .■ i 



6 Gray G. R. 1S32. Supplement on the order Diptera. Griffith s translation and 



revision of Cuvier's Animal Kingdom, 15: 779; PI. 128, Fig. 3. 

 7. Johnson, C. W. 1903. Ent. News, 14: 64. , ^ ^. oo 



■8. Johnson, C. W. 1915. Note on the species of the genus Acrocera, Psyche, ZZ: 



198-203. 

 9 Kertesz, C. 1909. Catalogus Dipterorum, Budapest, 4: 1-21. 

 10 Konig Anton. 1894. Ueber die Larve von Ogcodes, Verh. der zool-botan. 



Gcsel., 44: 163-166, PI. 7, Figs. 1-6. 

 11. Lundbeck, William. 1907. Acroceridae, Diptera Danica, Copenhagen, part 1: 



12 Malloch J. R. 1915. Some additional records of Chironomidae for Illinois and 



notes on other Illinois Diptera. Bull. 111. State. Lab. of Nat. Hist., 11: 

 .341-342; PI. 82, Fig. 23. ^^ , r, xt v i i 



13 Maskell, W. M. 1888. On Henops brunneus. 1 rans. and Proc. New Zealand 



Inst., 20: 106-108; PI. 10, Figs. 1-12. 



14 Melander, A. L. 1902. Notes on the Acroceridae. Ent. News, 13: 179. 



15. Menge, Anton. 1863-66. Preussiche Spinnen. Schrift. d. Danzig, nat. Gesel. 



N. Folge, 1: 37. , ■ , , , 



l(j. Montgomery, T. H. 1903. Studies on the habits of spiders, particularly those 



of the mating period. Proc. Acad. Nat. Sci. Phila., 55: 68. 

 17. Osten Sacken, C. R. •!77. West. Diptera. Bull, of U. S. Geol. Surv. of the 



18 Stein, Friedrich. 1841 Dipterologischer. Stett. Ent. Zeit., 10: 117-120. 



19. Williston, S. W. 1886. Dipterological notes and descriptions. Trans. Amer. 



20. Williston, S.'W. 1908. Manual of North American Diptera. New Haven, 182-185 



EXPLANATION OF PLATE XV. 

 Pterodontia flavipes. 



1. Dorsal aspect of female. 



2. Dorsal aspect of male abdon ?n. 



3. Wing of male. 



4. Egg as viewed from the side. 



5. Egg as viewed from above. 



6. Chorion highly magnified. 



7. Lateral aspect of young larva showing mouth-hooks and internal pharyngeal 



skeleton. ■ ■ r i. .u -j 



8 Dorsal aspect of mature larva as it appears after emerging from host spider. 

 8a. Lateral aspect of mouth-parts, m., mandible; m. h., mouth-hooks; ph. p., 



pharyngeal plate. 

 9. Lateral aspect of pupa. 

 9a. Clublike processes from head of the pupa. 



10. Young larvae in the body of Epeirid spider. 



EXPLANATION OF PLATE XVI. 

 Pterodontia flavipes. 



11. Dorsal aspect of newly hatched larva. 



12. Ventral aspect of newly hatched larva. 



13. Scale from mesonotum. 



14. Scale from mesosternum. 



15. Scale from sternum of third abdominal segment. 



16 Scale from sternum of seventh abdominal segment showing its insertion. 



