334 



The species was obtained by me at White Heath, 111., June 24, 

 191 6, from horse dung. 



MiCROCHRYSA Loew 



GENERIC CHARACTERS 



Larva and Puparium. — Very similar to the larva of Geosargiis, 

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

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



HABITS OF EARVAE 



The larvae feed upon manure or decaying vegetation. The species 

 hibernate as larvae. 



HABITS OE IMAGINES 



The flies have similar habits to those of Geosargiis. 

 MiCROCHRYSA POEiTA Linne 



Musca polita Linne, Fauna Suecica. (1761) 



Larva and Piipar'uini. — Length, 5-6 mm. Differs from Geosargiis 

 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 

 Geosargiis, 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 w^ere found in company with those of 

 Geosargiis viridis in cow manure at Muncie, 111., in April, 1916. They 

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

 dorsal markings readily separates the two. 



The imagines are not nearly so common as those of Geosargiis 

 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. Soe. Amer., Vol. 8, 1915, pp. 305-320. 



