Correspofidence. 335 
CORRESPONDENCE. 
Collecting Fossils in the Cinncinati Shales.— One of the mosl 
strikingfeaturesof the numerous collections of fossils of the Cincinnati 
district, examined by me, is the almost total absence of the forms oc- 
curring in the shales of that formation. For a long time no adequate 
explanation suggested itself for this conspicuous absence of the not 
only beautiful but highly interesting and valuable specimens which al- 
most invariably rewarded my efforts, when a resident collector in that 
justly famous locality. 
The reason which at last suggested itself to me is, that collectors 
being at a loss as to the proper time in which to work them, and as a 
consequence having had disappointing results, have come to regard the 
shales as unprofitable. 
Judging from my own experience, they offer advantages to the sys- 
tematic collector far superior in many respects to the weathered quarry 
dumps and natural exposures. Surface collecting and the breaking of 
rock have each its advantage, but to get the best results all should be 
worked together. 
The Pelecypoda of the shales, although occurring chiefly as casts of 
the interior, are otherwise nearly always found in an excellent state of 
preservation, '^specially as regards surface markings, which are often 
beautifully defined. On the contrary, those found in the soft limestone 
are with few exceptions so poorly preserved, as to be worthless for 
study. During the winter of 1895, and the early spring of 1896, I col- 
lected in about eight weeks more than one thousand specimens of pele- 
cypods, representing about one hundred and ten species, fully seventy- 
five per cent, of which were found in the soft shales. 
Besides the pelecypods, many species of other classes of fossils were 
found. Some rare forms of trilobites, crinoids and brachiopods being 
among them. 
The statement that these fossils were collected in the winter time 
may occasion surprise to some collectors, which is likely to become 
greater, when I assert that the winter and early spring is the proper 
season for successful work in the shales. 
Of course the winter must be sufficiently open to allow the quarries 
to be worked. The winter mentioned was of that kind, little snow 
having fallen and many days being warm and bright. 
In speaking of shale collecting, especial reference is had to the 
lumps of shale taken from their formations in the quarries. These 
should be allowed to remain for several weeks exposed to the snows 
and rains, to become thoroughly saturated with moisture. They can 
then readily be split with a geologist's hammer, or lifted layer after 
layer, with a strong, pointed knife blade, until each piece has been 
thoroughly prospected. Following very severe weather, the moisture 
in them having thoroughly frozen, the outside soon begins to crumble 
