June, 1915.] Fish-feeding Coieoptera of Cedar Point. 527 



than fish remaining on the beach. For a period of six weeks a 

 number of "traps" made by covering several fish with boards 

 were maintained at different places on the Point, and kept in 

 continual operation by frequently adding fresh supplies of fish. 

 Other traps similar in structure were moved from place to place 

 every few days. It was found that location had much to do with 

 the number of individuals present, and that the traps maintained 

 in regions of the deepest shade were most productive. Within 

 certain limits the number of individuals and species increased with 

 the age of the trap. In these traps larval forms of the families j 

 Silphidee, Staphy-linidae and Dermestidae were frequent. In the 

 aggregate members of the Histeridae were represented in larger 

 numbers as adults than any other family, but their larvae were 

 never present. 



During the early morning of July 25th, while making a trip 

 along the beach two carp were found, weighing about two pounds 

 each, not more than fifty feet apart, that had just been cast up 

 by the waves. Over one a box 14"xlS" was turned, protecting 

 the fish from the sun and the birds. The afternoon of the 28th 

 the box was removed and the sand for a radius of two feet from 

 the fish and to a depth of about a foot was carefully sifted and the 

 astonishing nimiber of 1310 adult Hister beetles, practically all 

 of them vSaprinus pennsylvanicus Payk were taken. Most of 

 these we found a few inches under the fish in the sand made wet 

 with the juices. Accompanying these were nine adult Dermestes 

 caninus Germ. To these might be added the five beetles taken 

 from the stomach of a small toad found under the box buried in 

 the sand. Only one of the five, however, was a fish feeder, it 

 being Saprinus pennsylvanicus. Hundreds of Dipteron larvae 

 were present, but not the slightest trace of beetle larvae save one 

 of Trox scabrosus. 



The sand around the unprotected fish of some size and kind, 

 already mentioned, was sifted but the result was the same as that 

 found at other unprotected fish examined at different times. 

 Of the beetles found at such times the Histers predominated in 

 numbers with an occasional member of the Staphylinidce and one 

 or two larval forms of Trox scabrosus. No other larval forms 

 of coieoptera were found, the fly larvae were always found in large 

 number. The total number of beetles found in these miprotected 

 fish never exceeded 100 and averaged about 50. 



Some writers suggest that the Hister beetles instead of being 

 carrion feeders may be predaceous, feeding on the larvae of flies 

 universally present in carrion. Several experiments in which 

 adult Histers were confined with fly larvas for several days with 

 and without other food failed to show one case where a fly larva 

 sacrificed its life to the Hister beetles. On July 31st, however, 

 the writer saw two adults of Silpha americana eating fly larvae 



