NATURAL HISTORY WORK IN CART A GO 65 



preceding night. We record this occurrence because it was 

 the only time during our entire year in Costa Rica that we 

 observed a bird feeding on Lepidoptera, We went there 

 very favorably disposed toward the theories of mimicry 

 and of protective resemblance. We expected to see many 

 instances of birds pursuing and feeding upon butterflies, and 

 frequently looked for such, but were utterly unsuccessful. 

 Our experience in this respect entirely coincides with that of 

 Mr. William Schaus in his three years in Costa Rica. 



Among the conspicuous insects which were attracted to 

 the electric lights in Cartago, as in other parts of the world, 

 were scarabaeid beetles, armed on the upper surface, in the 

 males at least, with prominent horns. Like their allies of the 

 temperate climes, the June bugs and chafers, they are heavy 

 blundering fliers and their size was frequently such as to 

 cause a momentary annoyance if they struck against one's 

 head. To one interested In the variety of form which Nature 

 displays, the horns off"er a field for much speculation. They 

 may be one, two or three In number and variously placed on 

 the head or the prothorax. 



Xyloryctes lobicollis, a dark brown scarabaeid an inch long, 

 which came to the Cartago lights in May, has a single sharp- 

 pointed rhinoceros-like horn, on the top of his head but no 

 horn on the thorax, although there is a low knob-like swelling 

 on the middle of that region (which is somewhat hollowed 

 out in front of and below the swelling). The female, of the 

 same size and color as her mate, has a shorter pointed cone 

 on the top of her head corresponding to his horn while her 

 prothorax is smooth and convex throughout with no indica- 

 tion of knob or concavity. 



Enema endymion came to the lights on the same nights 

 with Xyloryctes. He is longer — 1 3^ inches or more in 

 length — and wider — ^ inch as against '^/g — and of a much 

 redder brown; his wing-covers are much smoother and show, 



