JUAN VI N AS— THE REVENTAZON VALLEY 219 



off while the others only fluttered a short distance and re- 

 turned to the same roots and same positions. 



In April flocks or single individuals of a handsome butter- 

 fly, AncBa onophis^ were abundant, particularly at wet spots 

 along the road. The upper surface of its wings (which ex- 

 panded 23^ inches) was dark blue with pale blue spots near 

 the outer margin. Each hind wing had a slender tail 3^ 

 inch long. The under surface was colored brown and much 

 resembled a withered leaf so that the insect was inconspicu- 

 ous when at rest. 



On June 25 our attention was attracted by small moths 

 which settled on the rocks, both on the river bank and out 

 in the stream, an inch or two above the water surface. There 

 was no apparent cause for their positions, as in many in- 

 stances the rocks were bare and are no doubt frequently 

 submerged. On one rock in the stream about three feet 

 long we counted twenty-five of these moths, facing in differ- 

 ent directions. Their wings were bright orange, the outer 

 margins broadly edged with black, and expanded about i}^ 

 inches. Mr. Champion observed the same stream-fre- 

 quenting habit of this species {Nelo chrysomela) in the Chi- 

 riqui district of Panama. 



At different times some curious or interesting caterpillars 

 were met with along the Reventazon road. While A. was 

 sitting on a rock at the ford of the Naranjo on June 25 she 

 was startled by seeing walk toward her what looked like 

 a miniature skye terrier about three inches long. It was 

 a caterpillar (family Megalopygidae) thickly covered with 

 long silky hairs which on the front end of the body were 

 brown. The hairs of the greater part of the body were whit- 

 ish, beginning on the first abdominal segment and arranged 

 in correspondence with the segments. The head and protho- 

 rax had no long hairs, so that the brown ones above men- 

 tioned were borne by the other two thoracic segments and 



