ECOLOGY OF ISLE ROYALE. 315 



Argentina to Canada and from the Atlantic to the Pacific. Wiedemann's 

 types were taken in South America. The Isle Eoyale specimen has 

 less red at the tip of the abdomen than most Ohio specimens. 



The family Tachinidae contains a large number of species and nearly 

 all of them are of more or less interest to the economic entomologist on 

 account of their parasitic habits. Many injurious insects have one or 

 •more Tachinid parasites which aid in holding them in check. 



41. Echinomyia algens Wiedemann. Two specimens taken July 14 

 (III, 3) and July 26 at Light-house clearing (I, 7). The types were 

 taken in North America, but the exact locality is not given. Recent 

 writers have reported the species from many points in Mexico and north- 

 ward. It is said to be parasitic on the larvae of the moth, Hadena ligni- 

 color Guen^e. 



Family 8arcof>liagidac. 



42. Sarcophaga sarraceniae Riley. Flesh Fly. A specimen taken 

 July 11 at Light-house clearing (I, 7). This is our common flesh fly, 

 and is an important scavenger. Type locality Missouri. The species of 

 Sarcophaga are not well understood in America and it may be that this 

 is a synonym. However the name is included in many local lists of 

 Diptera which indicates a wide range for the species. 



43. Lucilia caesar Linn. Carrion Flv. Four specimens taken July 

 25 (II, 1), July 26 at Light-house clearing (I, 7) and August 5 (V, 3). 

 Known from Europe and America. A very common carrion fly every- 

 where. Along the shores of the Great Lakes its larvae feed largely 

 Tipon the carcases of fishes cast on the beach by the waves. 



44. Calloplwra viridescens Desv. Blow Fly. Three specimens taken 

 July 25 (II, 3) and August 7 (V, 3). This is one of the common blow 

 flies and is widely distributed in Europe and America. 



45. Cynomyia cadaverina Desv. Two specimens taken July 8 (I, 1). 

 Carolina is the type locality but the species is found in most localities 

 in the United States and Canada. 



46. Phormia terraenovae Desv. A specimen taken August 4 (V, 3). 

 Type locality Newfoundland. Generally distributed over North Amer- 

 ica, especially northward. 



Family JHuscidae. 



47. Musca domestica Linn. House Fly. A specimen taken August 

 7 (V, 3). This species needs no particular comment here. It is found 

 in nearly all parts of the world and has lately been proven to be con- 

 nected with the transmission of typhoid fever. 



Family Anthomyidae. 



48. Hyetodesia serva Meigen. Five specimens taken July 11, 23 and 

 24 at Light-house clearing (I, 7) and August 4 (V, 3). This European 

 species has been reported for America, but its distribution is not well 

 understood. I have compared these specimens carefully with Schiner's 

 description and find that they agree well, but as the group is very rich 

 in species their determination is not always an easy matter. 



