TURRUCARES AND RIO GRANDE DE TARCOLES 365 



Spanish daggers {Bidens) and the "pega-pega" or beggars' 

 ticks {Desmodium). The pasture west of this field had beau- 

 tiful soft green grass. 



Going down hill, behind — north of — the house, through a 

 pasture with a single palm in the middle of it, brought us 

 to the Rio Siquiares, a swift-flowing stream discharging into 

 the Rio Alajuela, which is in turn an affluent of the Rio 

 Grande de Tarcoles. The rocky bed of the Siquiares was in 

 the form of steps so that the descent of the flowing water was 

 well marked. The banks on both sides, shaded with medium- 

 sized and small trees, produced a pretty effect. A short 

 distance downstream, the river made a sharp bend, owing 

 to a wall of basalt, about fifteen feet high, with a distinctly 

 columnar structure, which jutted out from the left bank. 



Professor Alfaro and his son spent the afternoon of August 

 14 fishing in the Siquiares and caught five fish. Four were 

 put into alcohol. The fifth and largest, about six inches long, 

 was cooked for my dinner; it was a Rhambia, of the catfish 

 family, and good. 



On my first visit, two features of the plant life around 

 Turriicares struck me as the chief differences from the At- 

 lantic slope, which alone I had hitherto seen. One was the 

 much smaller number of bromeliads and epiphytes generally 

 on the trees, the other was the abundance of the bull's 

 horn thorns in the woods. These plants ranged from bushes 

 three feet high to trees of fifteen. In the preceding chapter 

 mention has been made of their peculiarity in being fre- 

 quently inhabited by small ants of the genus Pseudomyrma. 

 I saw Ps. belli which is black and Ps. nigrocincta which is 

 red with a dark band near the middle of the body, at Turrii- 

 cares. We had to be careful to avoid touching the bull's 

 horn thorns in passing them, for if we did so we were almost 

 sure to brush off some of the ants upon us, whereupon they 

 proceeded both to bite and sting severely. In some places, 



