National Geographic : 1915 Aug
THE LOW ENTRANCE TO THE BAT CAVE ON THE CHILIBRILLO RIVER OPENS INTO A SERIES OF LONG CORRIDORS AND CHAMBERS MORE OR LESS INTERCOMMUNICATING FLASHLIGHT OF A SMALL CLUSTER OF BATS BEFORE THEY WERE ALARMED Clusters are ordinarily formed of a great number of individuals, probably several hun dred in some instances. The variety shown is one of the largest of South American bats, one specimen secured having a wing expanse of 26 inches. The bats are strong and muscular and always ready to bite. The masses of bats bear a close resemblance in form to the stalactites with which the walls and domed ceilings are covered.