334 



The species was obtained by me at White Heath, III, June 24, 

 19 1 6, from horse dimg. 



MiCROCHRYSA LoCW 

 GIJNERIC CHARACTERS 



Larva and Piiparium. — Very similar to the larva of Geosargus, 

 differing as indicated in generic key, and in having a longer head. 

 Imago. — Brilliant metallic blue species, with rather stout bodies. 



HABITS OF LARVAE 



The larvae feed upon manure or decaying vegetation. The species 

 hibernate as larvae. 



HABITS OE IMAGINES 



The flies have similar habits to those of Geosargus. 

 MiCROCHRYSA POEiTA Linne 



Musca polita Linne, Fauna Suecica. (1761) 



Larva and Pnparinm. — Length, 5-6 mm. Differs from Geosargus 

 viridis in having the two pale stripes on dorsum entirely straight and 

 the central dark line complete. 



Head more slender anteriorly than in G. viridis (PI. XLIX, Fig. 

 2). Armature similar to that of viridis except that the bristles are 

 much longer. Apical segment more attenuated apically than in 

 Geosargus, the respiratory opening much smaller, not in the form of 

 a transversely elongated slit, and farther from apex than in that genus 

 (PI. XLIX, Fig. 3). 



Described from specimens from which imagines were obtained by 

 the writer. The larvae were found in company with those of 

 Geosargus viridis in cow manure at Muncie, 111., in April, 19 16. They 

 closely resemble the larva of Geosargus, but the difference in the 

 dorsal markings readily separates the two. 



The imagines are not nearly so common as those of Geosargus 

 viridis. 



Subfamily PACHYGASTERINAE 



I recently published a revision of the imagines of this subfamily*, 

 and students may refer to that for full information regarding species. 



*Ann. Ent. Soc. Amer., Vol. 8, 1915, pp. 305-320. 



