50 



DIPTEEA. 



Two specimens, easily recognizable from the description. The pile of the mesonotum 

 can hardly be said to be " sehr kurz " ; the peculiar dots on the fourth abdominal 

 segment are only visible in the female example. 



13. Volucella obesa. 



Syrphus obesus, Fabr. Syst. Ent. p. 763 1 ; Ent. Syst. iv. p. 282 2 j Syst. Antl. p. 227 3 . 



Volucella obesa, Wiedem. Aussereur. zweifl. Ins. ii. p. 199 4 ; Macq. Hist. Nat. Dipt. i. p. 494 5 ; 



Dipt. Exot. ii. 2, p. 21 6 ; Schiner, Reise der Novara, Diptera, p. 356 7 ; Willist. Synopsis N.-Ara. 



Syrphidfe, p. 143, t. 5. f. 9 8 ; Trans. Am. Ent. Soc. xv. p. 272 9 . 

 Ornidia obesa, St.-Fargeau & Serville, Encycl. Meth. x. p. 786 10 . 



Hab. United States, New Mexico 8 , Florida 8 .— Mexico 8 (H.H. Smith); Guatemala 

 (Champion); Costa Rica (Van Patten); Panama (Boucard).— Soutpi Amekica 5710 , 

 Colombia 6 , Guiana 6 , Surinam 6 , Brazil 4 6 9 , Chili 6 ; West Indies 3 , Cuba 6 , San 

 Domingo 8 , Guadaloupe 6 .— Bourbon 6 ; Isle of Feance 6 10 ; East Indies 6 . 



In the Central-American collections before me there are one hundred and twelve 

 examples of this brilliantly-coloured, cosmopolitan insect, from numerous collectors 

 and localities. The most interesting thing in connection with these specimens is the 

 very great variation in size— the smallest measuring only 9 millim. in length, while the 

 largest are 16 millim. 



14. Volucella esuriens. 



Syrphus esuriens, Eabr. Syst. Ent. iv. p. 281 1 ; Syst. Antl. p. 226 \ 



Volucella esuriens, Wiedem. Aussereur. zweifl. Ins. ii. p. 197 3 ; Schiner, Reise der Novara, Diptera, 

 p. 356 4 . 



Volucella violacea, Say, Journ. Acad. Phil. vi. p. 166 5 ; Coraplete Writings, ii. p. 360 6 . 



Volucella mexicana, Macq. Dipt. Exot. ii. 2, p. 25, t. 5. f. 3 7 ; Schiner, Reise der Novara, Diptera, 



p. 356 8 ; Osten Sacken, Western Diptera, iu Bull. U.S. Geol. & Geogr. Survey, iii. p. 332 \ 

 Volucella dispar, Macq. Dipt. Exot. l er Suppl. p. 123, t. 11. f. 2 10 . 

 Volucella maximiliani, Jaennicke, Neue exot. Dipt., in Abh. Senck. Ges. vi. p. 395 n . 

 Volucella metallifera, Walker, List Dipt. iii. p. 636 12 . 



Volucella esuriens mexicana, Willist. Synopsis N.-Am. Syrphida, p. 137, t. 6. tigg. 5, 5 a 13 . 



Hab. United States, California » 13 , Arizona 13 , Texas \ Florida 13 .— Mexico 5 6 7 9 11 12 , 

 Omilteme, Xucumanatlan, Amula, Mexico city (H. H. Smith), Jaral, Atoyac (Schu- 

 mann); Guatemala (Chamyion).— South Amekica 4 , Colombia 10 , Venezuela 12 ; West 

 Indies 1 2 3 . 



Thirty-four specimens. V. mexicana is probably inseparable from V. esuriens, and I 

 have so given the synonymy ; but should there be good ground for distinguishing it, 

 the name violacea, Say, ought to be used. 



