6 COSTA RICAN DIPTERA 



Ouebrada de Salas. — A brook a few rods east of Atenas Sta- 

 tion on the Pacific Railroad, but west of the bridge over the Rio 

 Grande de Tarcoles. Altitude 1600 to 1700 feet. It empties 

 into the Rio Grande de Tarcoles south of the railroad. Collec- 

 tions were made north of the railroad. Ver.y clear water, banks 

 of brook rocky, shady, with tall trees and undergrowth. Farther 

 up it flows through pastures. Salas is the name of the owner of 

 a farm through which it flows. 



Rio de las Canas. — A tributary of the Rio Tempisque, coming 

 from the western part of the northern end of the peninsula of 

 Nicoya, flowing northeastwardly and eastwardly and emptying 

 into the Tempisque east of Bolson. I collected on January 30, 1910, 

 at a place on this river approximately north of the town of Santa 

 Cruz. The river banks here were low and muddy with low twisted 

 trees and low plants standing in the shallow water. 



Rio Reventado. — On the southern slopes of Irazu volcano, 

 a small rocky stream with fairly swift current, a short distance 

 west of Cartago. Altitude 4650 to 5000 feet where collections 

 were made. 



Rio Reventazon (near Juan Vifias). — Altitude of the river here 

 2500 feet. Flows in the bottom of wooded valley 1500 feet deep. 

 Valley sides steep. Various small brooks empty into river at 

 short intervals. These and the rains make many moist spots. 

 Here and there the bottom of the valley is wide enough to allow 

 planting maize and other food-plants. On the valley sides many 

 large forest trees, chiefly exogens, and much undergrowth. (See 

 also Juan Vifias.) 



Rio Segundo.— (See Alajuela.) 



Rio Surubres. — A small tributary of the Rio Machuca on the 

 Pacific slope. Our collecting was done near the Bonnefil Farm, 

 where we were guests of Senor Pedro and Senorita Josefina Bonne- 

 fil. Altitude about 800 feet. The ravine occupied by the river 

 is well wooded with a great variety of trees and there are also nu- 

 merous species of plants in the undergrowth. The river was to the 

 east and south of the farm. To the west and north was "charral," 

 pasture that had subsequently grown up with bushes, patches of 

 grass, thorny vines, and some palms (cojol palm, Acromia vini- 

 fera, royal palm, Oreodoxa regia, and peji-baye, Guilielma utilis), 

 guanacaste (Enterolobium) etc. 



