56 H. C. EFFLATOUN. 



sometimes occur in great swarms amongst which be mentions S. 

 corolla?, Lasiojrfithieus pyrastri and S. balteatus ; they "appeared 

 to have all hatched simultaneously, and to have at once commenc- 

 ed buzzing about in the sunshine in a foolish kind of way, without 

 earing to take food, for most of them seemed to be mere shells 

 without any substance inside"; the date of the occurrence of the 

 two and only swarms is August 24th. This genus is one of the 

 largest in the family and now includes about 350 species recorded 

 from practically every part of the world. 



TABLE OF EGYPTIAN SPECIES. 



1 (2) Length of abdomen less than twice its breadth ; 



abdominal spots very conspicuous, rather lunul- 

 ate and extend over the side margins (PI. IV, 

 figs. 2, 3) 1 corollas Fabr. 



2 (1) Length of abdomen more than twice its 



breadth; abdominal spots do not reach the 

 side margins. 



3 (4) Abdominal bands duplicated (PI. IV, fig.6) 2 balteatus Dec 



4 (3) Abdominal bands very emarginate, or separat- 



ed into triangular spots, (PI. IV, tig. 1). . 3 auricollis Meig. 



,. S. COROLLAE FABR. (PI- IV. figs. 2, 3). 



Fabr., Entom. Syst,, IV. 306.103. (1794) et Syst. Antl., 250.8. 

 (Scceva). (1805); Meig., Syst. Beschreib., III. 304.46. (1882) ; Macq., 

 Rec. Soc. Sci. Lille, 1828.239.23. (1829) Suit, a Buff., 1.539.18. 

 (1834), (in Webb et Berth.) : Hist, Nat. d'lles Canar., Entom., 

 Dipt., 109.49. (1838) et Explor. Scient. Algerie, Zool., III.469.l70. 

 (1849); Wied., Aussereurop. Zweifl. II. 121.7. (1830); Brulle, 

 Exped. Scient. de Moree, III. 1., 310.669. (1832); Lw. Verb, zool.- 

 bot. Ver. Wien., VII. 80.32. (1857), Programm. Posen, 1840.34.4 

 (1840) et Isis, 1840. VIII. 572.4. (1840); Zett., Ins. Lappon., Dipt,, 

 602.16. (Scceva) (1838), Dipt, Scand., II. 720.23. (Scceva) (1843). 

 Dipt. Scand., VIII. 3138.23. (Scceva) (1849) et XII. 4657.23. 

 (Scceva) (1855); Walk., List Dipt, Brit. Mus., III. 583. (1849) et 

 Ins. Britann., Dipt., I. 289. 9. (1851); Schin., Verh. zool.-bot, 



