PROCEEDINGS OF THE NATURAL 
138 
[April, 1887. 
county, and that only one species of the Parnidx is common, 
Helichus lithophilus. 
Thus far we have considered only the littoral distribution of 
Coleoptera in space. It remains for us to consider this distribu¬ 
tion in time. My attention was first directed to the distribution 
of Coleoptera in 1879. Mr. Rauterberg, whose accuracy as an 
observer and whose pains and diligence as a collector are well 
known to us all, states that previous to this date the number of 
Coleoptera found on the beach, even within the city limits, on 
that part of the shore since improved by the railroad, was truly 
wonderful. He has told me frequently, that he has filled bottle 
after bottle in a few minutes, that he could almost shovel the 
specimens up. From 1879 to 1883 we both observed tbe distri¬ 
bution and have noticed a steady decline in the number of spec¬ 
imens during these five years. Being absent from town during 
1884 1 was unable to continue my observations, but Mr. Rauter¬ 
berg says that he could obtain but very few beetles. During 
the last summer, 1885, repeated visits to the beaches, which in 
former years had yielded such a rich harvest, were rewarded by 
nothing. How are we to explain this? We cannot consider 
this problem without regarding the distribution in time through¬ 
out the county. There seems to have been a slight decrease in 
e number of Coleoptera inland, but a decrease scarcely suffi- 
r r Pl T , abrupt fallin S off in the littoral distribution. 
oTel!r T f dt0aSkthe qUestion: Can the building 
witltil hi ? T™ 0flate years fcave anything to do 
xn anvwa ? Z " ^ W defle <^ the lake currents 
enlJ Zl " T eSti ° n 1 am nnable to answer. More 
count naturarT * ° bservatio ^ on the part of our 
Ct:^trt ar T? Ulred ’ b0th ° n this Point and on many 
otneis touching this distribution p PP i,„ . , 
“ Math ° f *•-* 
the different season^ has Wit si'it^1^ diStribution throu 8 hout 
tion of the inland species ultane °us with the distnbu- 
- early spring waL-beetles am"" Ws “ 
almost the only Coleoptera 
