NOTES ON THE MUSCOID FLIES OF THE GENEKA 

 OPELOUSIA AND OPSODEXIA WITH THE DESCRIP- 

 TION OF THREE NEW SPECIES 



By H. J. Reinhard 



Of College Statimi, Tex, 



During March, 1921, while collecting Diptera at College Station, 

 my attention was drawn by the presence of several small snails which 

 were situated on tree trunks, 3 or 4 feet above the ground. The 

 snails appeared normal and were quite firmly attached to the sur- 

 face, but upon removing a specimen it was found to contain a dip- 

 terous puparium. Further search resulted in taking 16 additional 

 parasitized specimens, each with a single puparium located in the 

 basal end of the chamber. The puparia were placed in breeding 

 cages and 5 male and 12 female flies issued from March 30 to 

 April 15. Judging from the early date of collection, it appears more 

 than likely that this parasitic fly hibernates in the pupal stage within 

 the shell of its host. Examples of the snail were sent to the United 

 States National Museum, where they were determined and acces- 

 sioned as Succinea luteola. Recently Dr. J. M. Aldrich determined 

 the parasite reared from this mollusk as Opelousia ohscura 



Townsend. 



Genus OPELOUSIA Townsend 



The genus Opelousia Townsend, with ohscura (new species) as the 

 type, was erected in 1919 ^ for the reception of four male specimens 

 collected at Opelousas, La., and Fargo, N. Dak. Since the original 

 characterizations are brief, lacking in essential data, and do not in- 

 clude the female, a description of this sex is included below with the 

 description of an apparently new species. 



OPELOUSIA OBSCURA Townsend 



Opelousia obscura Townsend, Proc. U. S. Nat. Mus., vol. 56, 1919, p. 547. 

 Female. — Blackish brown, thinly cinereous poUinose, subshining. 

 Eyes bare. Front 0.34 of head width (average of six, 0.34, 0.38, 0.33,. 



1 Proc. U. S. Nat. Mus., vol. 56, p. 547. 



No. 2817.-PROCEED1NGS U. S. NATIONAL MUSEUM. VOL. 76. ART. 20 

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