144 INSECUTOR INSCITlyt MENSTRUUS 



NEW MUSCOID FLIES, MAINLY HYSTRICIID.^ AND 

 PYRRHOSIINyE FROM THE ANDEAN MONTANYA 



By CHARLES H. T. TOWNSEND 

 Director of Entomological Stations, Lima, Peru 



The flies described in this paper were all collected by myself, except 

 in the few cases that are duly noted. The Andean localities may be 

 briefly described as follows : 



Uruhuasi Bridge is in the canyon of the Rio San Gaban, at an altitude 

 of about 6,500 feet, on the eastern slope of the Cordillera Oriental in 

 southern Peru. The Rio San Gaban flows into the Rio Inambari, which 

 is a branch of the Rio Madre de Dios, one of the principal heads of the 

 great Rio Madeira system. Uruhuasi is situated at about the upper limits 

 of the tropical rain forest, where the latter thins out and finally gives way 

 on the slopes to the scrub forms of woody vegetation which characterize 

 the higher levels. Ollachea is above Uruhuasi in the same canyon at 

 about 9,500 feet, closely shut in by towering mountains and ridges. 

 Casahuiri is below Uruhuasi in the same canyon, at about 4,500 feet, 

 and well within the forested region. 



Huascaray Ridge is in the Cordillera Oriental of northern Peru, on 

 the boundary between the departments of Piura and Cajamarca, separat- 

 ing the two provinces of Huancabamba and Jaen respectively thereof. 

 The locality where the collections were chiefly made is on the eastern 

 base of Huascaray, at about 7,000 feet, in the extreme western border 

 of Jaen province. It is on the headwaters of the Rio Tabaconas, which 

 flows into the Rio Chinchipe, one of the northern affluents of the Rio 

 Maranon or mountain course of the upper Amazon. 1 he tropical reiin 

 forest throws dilute arms up the valleys of this region, one of them reach- 

 ing the eastern base of Huascaray. Charape or Hacienda Chcirape is 

 well below Huascaray, in the Rio Tabaconas valley, at about 3,700 to 

 4,000 feet. The Rio Charape is a very small stream flowing from the 

 north into the Rio Tabaconas at Charape. The collecting was done 

 about a league up the Rio Charape, at about 4,500 to 5,000 feet, 

 where the true tropical rain forest throws one of its denser arms over the 

 hills. The Rio Tabaconas valley from Charape both up and down is 

 more open than is this quite heavily forested locality up the Rio Charape. 



The Rio Chira and the Rio Casma are in the low coast region of 

 Peru, in the departments of Piura and Ancachs respectively, the former 



