22 H. C. EFFLATOUN. 



obviously placed before the middle of cell M2, seems to exclude the 

 possibility of any relationship between these genera. 



The larvae undoubtedly feed on Aphides. I have caught P. 

 tibialis and its two well known varieties hovering over Sonchus in 

 the Mariout District. Mr. F. A. Willcocks has bred the larvae of 

 P. mgyptius on Aphis gossypii and Hyalopterus pruni on Apricot 

 in Ghezireh. 



SYNONYMY.— This genus was established by Latreille in 1804 

 for Mulio bicolor of Fabricius and Verrall states that there has 

 never arisen a doubt about the synonymy or limits of the genus. 



TABLE OF EGYPTIAN SPECIES. 



1 (2) Face with a black middle lines in both sexes ; 



scutellum entirely black in both sexes (PI. I, 



fig. 6), 1 tibialis Fall. 



2 (1) Face entirely whitish-yellow or yellow in both 



sexes; scutellum with the tip or often the 



lower half yellow in both sexes (PIT, fig.5) . 2 aegyptius Macq. 



i. P. TIBIALIS FALL. (PI. Ill, figs. 2, 3, 4). 



Fall., Dipt, Suec. Syrph., 60.5, pp. (Pipiza) (1817) ; Meig., 

 System. Beschreib., III. 183.13. (1822); Macq., Rec. Soc. Sci. Lille, 

 1828.187.6. (1829) et Suit, a Buff., I. 567.14. (1834) ; Zett., Ins. 

 Lapp., Dipt,, 618.2. (1838) et Dipt. Scand., II. 852.6 (1843) ; 

 Schumm., Ubers. d. Arb. u. Verand. d. schles. Ges. f. vaterl. Kultnr, 

 1842.164. (1842); Zett., Dipt. Scand., VIII. 3188.6. (1849); Lw., 

 Verh. zool.-bot, Ver. Wien, VII. 80.30. (1851) et Dipterenf. 

 Siidarr., 294. (366) (1860); Schin., Verb, zool.-bot. Ver. Wien, VII. 

 303.8. (1857), Fauna Austr., Dipt,, I. 257.1. (1862) et Nov. Reise, 

 Dipt,, 339.103. (1868); Bonds., Finl. tvaving. Ins., I. 284.3. (1861); 

 Walk., List Dipt, Brit, Mus., III. 544. (1849) ; Malm., Goeteb. 

 Kongl. Vet, Hand!., 70. (1863); Willist., Bull. Unit. Stat. Nat. 

 Mus., (31), 19. t. I; f. 8. (1886); Neuhaus, Dipt. Marchica, 90. 2. 

 (1886); Strobl, Mittheil. Naturwiss. Ver. Steiermark, XXIX. 

 1892.197. (1893); Snow, Kansas. Univ. Quart., III. 227. (1895); 

 Towns., Psyche, VIII. 140. (1897); Verr., Brit. Fl, VIII. 150.1. f 



