NO. 5 MAMMALS OF PANAMA GOLDMAN 9 



or a peak in its vicinity, was clearly visible. The outlook from a 

 towering rock showed that our route had been well chosen as it had 

 led steadily upward while jumbled ridges lay to the right and left 

 across deep canyons ; but we were separated from the mountain by a 

 rugged depression several hundred feet deep beyond which the main 

 peak rose almost sheer at least 1,000 feet above us. A steep slope to 

 the right appeared practicable for an ascent to the top, but several 

 days had been devoted to working up to this altitude in almost steady 

 rain. With heavy showers frequently recurring and hampering 

 operations, specimens could not be dried and began to mold, and we 

 were forced to retrace our way down the river to Porto' Bello where 

 we arrived the evening of June 9, and returned to the Canal Zone, 

 June 14. 



Field operations became increasingly difficult owing to the heavy 

 rains and it was decided to discontinue them for the season. I sailed 

 for New York June 24 on the steamer " Colon " and arrived in 

 Washington, June 30. 



At the end of the rainy season plans were matured for continuing 

 field work in the Canal Zone under the same auspices, and I left 

 New York for the Isthmus January 9, arriving at Colon on the 

 steamer ''Panama" January 15, 1912. Comfortable and convenient 

 quarters at Empire were assigned to me by the Isthmian Canal Com- 

 mission, and work was at once resumed, largely along the line of the 

 Panama Railroad. My Costa Rican assistant of the previous year, 

 Adan Lizano, was unable to rejoin me and I engaged George G. 

 Scott, who rendered faithful and efficient services throughout the sea- 

 son. Special attention was given to the Gatun Lake area, in the lower 

 parts of which final preparations were being made for raising the 

 water level. Many old houses in process of being demolished af- 

 forded unusual opportunities to capture specimens of rare bats. For 

 this same purpose a trip was made about the end of January to caves 

 on the Chilibrillo River, a small tributary entering the Chagres River 

 near Alhajuela at the extreme upper end of the proposed lake basin. 

 The caves were reported to contain remarkable colonies of bats, 

 which would be driven out by the rising water. Water was found 

 flowing through the caves which were formed by large rifts in the 

 limestone formation with numerous lateral chambers resulting from 

 water erosion. One of the larger of the latter was circular, 30 to 

 40 feet in diameter and about 25 feet from floor to roof. This 

 chamber was totally dark and to the roof large bats of the genus 

 Phyllostomus were clinging in dense patches. Several tons of bat 



