158 PROCEEDINGS OF THE NATIONAL MUSEUM vox.. i04 



It should be mentioned here that the types of several of the species 

 described in this paper, along with most of the larvae collected during 

 the study, have been deposited in the collection of the U. S. National 

 Museum. 



In studying many of the specimens, it was necessary to extract the 

 genitalia, particularly of the males. This was done by relaxing the 

 specimens in a humidor for several days and then removing the genital 

 caspule and genitalia under a dissecting microscope. The capsule 

 and genitalia were then mounted on a card point on the pin beneath 

 the specimen. When it was necessary to relax a specimen rapidly, 

 it was placed in water just at the boiling point for three minutes, 

 which was ordinarily enough time to completely relax it. Unfor- 

 tunately, this method usually changed the hue of iridescent species. 



In studying the genitalia a few were cleared in potassium hydroxide, 

 but all drawings were made from genitalia that had not been cleared. 

 The drawings were made using a binocular dissecting microscope with 

 a net reticule at magnifications of 45 X and 90 X . In some of the larval 

 illustrations a compound microscope was used to check and to fill in 

 detailed structures. Larval dissections were done with a small blade- 

 like probe, several insect pins, and a fine pair of dissecting scissors. 



The problems encountered in the biological studies were numerous 

 and sometimes exasperating. The adult Geotrupinae are quite 

 secretive, spending much of their life in deep burrows. There have 

 been a number of notes, written by Mohr (1943), Frost (1929), Park 

 (1931), Young (1950), and others, on collecting the adults at dung, 

 fungi, and decomposing animal and vegetable matter. At first, col- 

 lecting was done by looking for the burrows near dung and fungi. 

 However, this method was slow and much time was consumed digging 

 out a few beetles. In sandy areas the time necessary for digging 

 was greatly shortened by the use of a posthole digger. There the 

 burrows were almost vertical, and, when marked with a straw thrust 

 into them, they could be easily followed by digging beside the burrow 

 with a posthole digger and using a trowel to follow the burrow. If 

 it was a question of merely obtaining the specimen at the bottom of 

 the burrow, it was excavated with the posthole digger and the dirt 

 sifted through a quarter-inch mesh screen. 



In many cases it was difficult to locate burrows, particularly when 

 the ground was covered with litter. In order to obtain a sufficient 

 number of adults to use in rearing cages, various methods of trapping 

 were tried. Spector (1943) noted a number of Geotrupes attracted to 

 chicken feathers. Elaborating on Spector's observation, I covered 

 the bottoms of apple crates with fine screen wire. These were sunk 

 into the ground, partially filled with soil, and a layer of chicken feathers 

 and entrails placed on top of this. This method of trapping yielded 



