Variations of the Ordovician of Indiana. — Focrstc. 97 
to be very rare. The species is probably represented by Fig. 
Id, of Plate 8, Ohio Pal., Vol. I, 1873. 
In the Corryville bed along the eastern bank of the White- 
water at Brookvillc is found in considerable numliers a form 
of Dalmanclla closely resembling the species which is so 
abundant in the lower part of the Waynesville bed, provision- 
ally called /). jugosa. It is associated here with Bytliopoi'a 
gracilis, Callopora ramosa, Heterotrypa inflecta, Homotrypa 
obliqiia, and Lcptoirypa claT'acoidea. At New Trenton it oc- 
curs in much smaller numbers in the Corryville bed, assoc- 
iated with the same bryozoans ; it is found occasionally also in 
the J\ fount Auburn bed, associated with Platystrophia lynx, 
Coeloclcuia oivcni, and undescribed Mount Auburn forrns of 
Eridotrypa and Dckayia; it is fairly abundant at the base of 
the Warren bed, associated with Homotrypa pnlchra and 
Coeloclcuia ozveni, species occurring also in the Mount Au- 
burn bed, Coeloclcina oivcni being usually diagnostic of the 
Mount Auburn. 
In various parts of Franklin county, Dahnanclla is very 
common in the upper part of the Warren bed : Southeast of 
Fairfield on the L. J. Logan farm it is common both below ar^ 
above the Dinorthis rctrorsa horizon. Along Templeton creek, 
a diird of a mile east of the Brookville pike, it is abundant. 
At the Bauman locality southwest of Brookville it occurs in 
the upper part of the Warren bed. About a third of a mile 
above the mouth of Pipe creek, where the hill land reaches 
the creek, Dalmanclla occurs for at least 10 feet both above 
and below the Dinorthis rctrorsa horizon, the latter being 35 
feet below the top of the Warren bed. The Warren bed form 
of Dalmanclla closely resembles the species which character- 
izes the Dalmanclla zone of the Waynesville bed. 
There is no doubt that the form characterizing the Dal- 
manclla zone of the Waynesville bed was the form for which 
the name Dalmanclla jugosa was originally intended since this 
is the only form in the upper beds of the Cincinnati Group 
which can be said to be abundant. Its width often is seven- 
eighths of an inch, occasionally one inch. In local collections 
a small variety, slightly exceeding one-half inch in widdi, is 
often labelled Dalmanclla jngosa; both valves are more con- 
vex than in the larger specimens ; this variety occurs in the 
