92 INSECUTOR INSCITI^ MENSTRUUS 



very broad. Posterior third of fifth segment and all of sixth 

 and seventh highly polished, bright steel-blue. Legs, including 

 coxae, deep black, the femora bright yellow at base, the hind- 

 most pair narrowly so, the others to well beyond the middle. 



Four specimens representing both sexes, two from Santo 

 Domingo and two from Porto Rico, are before me. One fe- 

 male has the hyaline portion in the middle of the wing extend- 

 ing from the discal cell to the inner margin. In all other de- 

 tails the specimens agree closely. 



Baccha cylindrica appears to be exclusively Antillean. Cer- 

 tain specimens from the southern United States closely ap- 

 proach it in wing-pattern and at first glance one would pro- 

 nounce them conspecific ; but other characters show that they 

 really belong to Baccha fuscipcnnis. Typical specimens of 

 this latter species have the wings heavily and uniformly infus- 

 cated, showing only a more or less clear apical spot in the posi- 

 tion above described for cylindrica. In some Florida specimens 

 the hyaline is still more extensive, being broadly continuous 

 from the discal cell along the inner margin to the base of the 

 wing. This is the form described and rudely figured by Mac- 

 quart under the name Ocyptamus fascipennis (Hist. Nat. Ins., 

 Dipt., 1834, vol. 1, p. 554, pi. 12, fig. 13), from a specimen 

 coming from Philadelphia. 



Baccha fuscipennis, in spite of the variation in wing-pattern, 

 may be readily distinguished from cylindrica by the following 

 dififerences which a large series shows to be constant: The 

 third antennal joint on its inner side has a yellow spot at base 

 below. The legs are dull yellow shading to pale brown, the 

 femora showing very faint subapical darker bands. The abdo- 

 men is yellow-brown, the second to fifth segments with sub- 

 apical ill-defined dull black bands, that on the fourth segment 

 less extensive than in cylindrica. 



Eristalis meigenii Wied. 



Eristalis meigenii Wiedemann, 1830, Aussereurop. zweifl. Ins., 



vol. 2, p. 177, pi. 10b, fig. 15. 

 Eristalis meigenii Arribalzaga, 1892, Anal. Soc. Cient. Argent., 



vol. 34, p. 115. 



