THE HAMILTON ASSOCIATION. 119 
supposed to be worthless.. Now, such are the very things most 
eagerly sought after to determine the classification of the vari- 
otis families. The writer finds much difficulty at times in dis- 
tinguishing “ Acanthograptus ” from “ Inocaulis.” When the 
former has been compressed the characteristic Spines disap- 
pear altogether in some instances. 
The “Inocaulis bella”’ (Hall), figured in the geology of 
Ohio, appears to me to come under the head of Professor Spen- 
cer’s Genera. However, since he has not claimed it as such, 
nothing more need be said on this point. The cellules of 
“Tnocaulis ” are found displayed on the surface of the Frounds, 
not at the side of the branch. The writer has no recollection 
oi having seen a case where the cellules were exposed in any 
‘ Acanthograptus,” although anxiously sought for by himself 
and cthers. Possibly the Spines themselves may represent the 
parts indicated, but nothing is actually known respecting “the 
cell apertures” of the Genera to any of the members of the 
Section. 
THE CITY QUARRIES. 
The Webber quarry (a portion of which is worked by the 
corporation) until quite recently presented very few specimens. 
some of the Graptolites obtained, chiefly from the Chert, were 
in fair preservation when found a little below the upper or 
giaciated layer, but the greater portion seen of late were so 
weathered or decayed as to render them perfectly useless. In 
some cases the outlines were discernable at first, but on wash- 
ing the stone they lost branches or disappeared altogether. 
This is the more provoking, since the writer expressed his be- 
lief that they would put in an appearance at or about the point 
reached in quarrying on the surface of the layers there. The 
cause of their condition was ascertained to be the irregular dis- 
tribution of the protecting “Erie clay.” In places, on strip- 
ping the overlying soil, it was found to be absent, which per- 
mitted rain, snow or frost to penetrate and rot away the Chert 
beds beneath. The few well preserved Graptolites owe their 
preservation to patches of clay above them, probably. 
