4 COSTA RICAN DIPTERA 



southern slopes the land is mostly in pasture, maize or potatoes. 

 There are many small streams. (I never collected on the north 

 slope of Irazii which is much more wooded.) 



The floor of the highest crater of the volcano is about 10,600 

 feet above sea level; where the trail from Cartago crosses the 

 ridge to descend into the crater, the altitude is about 10,800 feet. 

 The highest point of the whole mountain is on the rim of the highest 

 crater and is 11,300 feet. The various craters — there are ten in 

 all — have much black volcanic sand with blocks of stone of all 

 sizes, and many kinds of plants and even low trees up to 15 feet 

 in height. 



Juan Vinas. — The railroad station is at 3400 feet altitude and 

 lies in the floor of an old crater, apparently. The most of this 

 crater floor has been marshy and hence called "laguna." Some 

 ditches have been cut to drain it and others were planned. A 

 large part of the sides of this crater was planted in coffee. The 

 village of Juan Vinas is about two miles from the station at 4000 

 feet altitude. It lies in the midst of open fields. The "nearer" 

 and "farther" waterfalls were on the railroad track a short distance 

 west of the station. Our headquarters were opposite the station 

 and practically at the same level. A road ran up from the sta- 

 tion to the village, another down to the Rio Reventazon and crossed 

 it (2500 feet altitude) by a bridge. (See also under Rio Reven- 

 tazon.) 



The brook in woods near mile post 74f of the Costa Rica Rail- 

 road, at which collections were made on May 2, 1910, was west of 

 Juan Vinas station, lies in woods with small palms, a few low tree- 

 ferns and arums on its banks and has a less rapid current than 

 many streams of the neighborhood and descends by steps rather 

 than by a continuous slope. Other plants in its immediate neigh- 

 borhood were Avild ginger (Costus), heliconias and caladiums. 

 Altitude about 3500 feet. 



Laguna del Dirumbo. — Also called Laguna del Reventado. 

 A pond of shallow water, formed by natural or artificial barriers, 

 on the upper course of the Rio Reventado on the south side of 

 the volcano Irazu at 9100 feet altitude. It lies in a little flat- 

 bottomed valley, and at the time I collected there (July 13, 1909), 

 was about 100 feet long by 75 or 80 feet wide. There were many 

 evergreen oaks (both dead and living), some baml^oos and much 



