298 PROCEEDINGS OF THE NATIONAL MUSEUM vol. i04 



worm holes instead! This reference should and would have been left 

 in the obscurity it deserves had it not been the one reference to the 

 genus used by the late G. J. Arrow (1951) in his book "Horned 

 Beetles." In this book, Arrow's statements on biology do not seem 

 to be based on any personal field experience. His section on Bolboceras 

 armiger is one such case. He cited Saunder's reference, which stated 

 that even though the beetles were found beside the worm holes, "the 

 same burrow never produced both worm and beetle." After quoting 

 this reference, which at least should have given rise to some doubts, 

 Arrow said (1951, p. 48), "It is clear that this insect escapes the neces- 

 sity of excavating its own burrow, for which the male is so unsuitably 

 equipped, by adopting a ready-made one. Can there be some 

 connection between the extravagant development attained by the 

 horns and the abandonment of the labours for which, in related species, 

 they are found useful accessories?" If Arrow had ever placed a live, 

 well-armed, male Bolboceras on hard ground and observed its actions 

 he would not have made the above statement but would have con- 

 cluded that it was an excellent burro wer. 



The biologies of some of the North American representatives of the 

 genus Bolboceras are better known. The adults of Bolboceras darlingtoni 

 have been found feeding on species of Rhizopogon by Sim (1930, p. 

 144) and myself. Other Bolboceras were collected by using fermenting 

 malt as an attractant, which would presumably indicate that they 

 feed on some decomposing materials. 



During the course of the present work a considerable amount of 

 information was accumulated on Bolboceras darlingtoni and liebecki. 

 Both species were found to provide for their larvae finely divided 

 surface humus, which they packed into the bottom of their burrows. 

 The former species deposits a single egg in a small cavity just beyond 

 the packed humus (pi. 14, fig. 1). The larvae, after hatching, burrow 

 through the humus, rapidly becoming third instars. Before pupation, 

 the larvae leave the food, burrowing about an inch to one side where 

 they make pupal cells (pi. 10, fig. 1), emerging as adults shortly there- 

 after. Development from egg to adult takes two to three months. 

 Whenever larvae were found, an adult, either male or female, was 

 found in the same burrow or in an adjoining one. What the relation- 

 ship between the adult and larva was, if any, could not be ascertained. 

 While there was a long period when adults of most species could be 

 found, the times of surface activity varied — darlingtoni, alabamensis, 

 and jloridensis being active in the fall, winter, and spring, while the 

 other species were found in the spring and summer. 



The genus Eucanthus, which is largely confined to North America, 

 has been found by the writer to have habits seemingly similar to those 

 of Bolboceras. Pairs of adults were found in burrows during the winter, 



