1977] 
Peck — Small Carrion Beetle 
301 
Figures 1-7. Structures of Prionochaeta opaca Say. 1. Habitus of male. 2. Left 
maxillary palp. 3. Protibial tip and enlarged male protarsus. 4. Mesotibial tip and 
unexpanded male mesobasitarsomere. 5. Large internal spur of posterior tibia. 
6. Dorsal view of aedeagus, setae on internal face of parameres omitted. 7. Lateral 
view of aedeagus. From Jeannel, 1936. 
similar situation is suggested for many arthropods (personal data). 
The species probably does not occur in peninsular Florida because 
extensive trapping there by Dr. Allred Newton and myself has 
failed to find it. Another disjunct population is in the forested 
Black Hills of western South Dakota. This population is separated 
from the rest of the species’ range to the east by the grasslands of 
the Great Plains. The beetle undoubtedly reached the Black Hills 
when the intervening country was more forested (with at least 
more extensive streamside gallery forests) during a cooler and 
more moist glacial period. It has become isolated with the expan- 
sion of the prairies in the warmer and drier climate of the present 
interglacial. 
Habitat preferences and feeding biology. Most specimen records 
show that the preferred habitat of the species is in moist and 
