38 Uniz'ersity of Michigan 



above the railroad, but brackish below that point. Collected 

 May 25-30, 1909. 



At this small stream Hetaerina fitia was very common, 

 more frequently over fresh water, but observed also over 

 nearby brackish water. On a stream farther up the railroad 

 track, which was entirely brackish where we explored it, no 

 Hetaerinas were seen. On the stream where titia was com- 

 mon two specimens of miniata were taken. No others were 

 seen. 



33. Rio Frio, Colombia. On the railroad about 48 kilo- 

 meters from Santa Marta. Elevation probably about fifty 

 feet. A fine, clear, swift stream, the Rio Frio, 40 to 60 feet 

 wide, crosses the track here. At this season it could be waded. 

 Trees grew to the water's edge. Back of Esperanza Farm is 

 the quebrada de Calabacito, which disappeared in the low- 

 lands, but back in the hills was a stony stream of running 

 water with pools six feet wide and ten to twelve feet long, 

 with about two feet as a maximum depth. Streams were gen- 

 erally absent at this season in the semi-arid chaparral, but 

 irrigating ditches to a certain extent took their place. Col- 

 lected January 6-8, 1917. 



On the quebrada de Calabacito we found both Hetacrina 

 macropus and caja, the former twice as numerous as the latter, 

 but neither abundant. On the Rio Frio also both species 

 occurred rarely, but here caja was more numerous than macro- 

 pus. On a large irrigating ditch we found only caja, which 

 f^ew there in large numbers. 



34. Rio Mcuzmnba, and 



35. Rio Sardanilla, two small streams, crossed by the rail- 

 road. Canal Zone, Panama. The Rio Mazamba was collected 

 December 6, 1916, only in its lower part near the railroad; 

 but the Rio Sardanilla was followed on December 5, 1916, 



