269 
[Foerste. 
another. On a glabella 6 mm. long the posterior furrows were 
.7 mm., the middle 2 mm., and the anterior 3 mm., distant from the 
posterior margin. All of these furrows are very shallow, and the 
inner detached extension of the anterior furrows could not be dis- 
tinguished at all. The fixed cheeks are strongly convex, and sharply 
defined posteriorly by the extension of the occipital furrow. A 
specimen retaining the glabella, occipital ring and fixed cheeks is 
5.2 mm. in length and 7.3 mm. broad. 
The corresponding proportions for a specimen, similar to our 
largest glabella, would be a length of 7.5 mm, and a breadth of 
10.5 mm. 
The pygidium found with this head is strongly convex, semi-cir- 
cular, broader than long, with the median segment very well defined 
from the lateral lobes. 
The following measurements will perhaps sufficiently illustrate the 
character of this pygidium. The posterior segments and pleurae be- 
come rapidly indistinct ; this is especially true of the pleurae which 
are rarely well marked beyond the fourth pair. 
LENGTH IN MM. 
BREADTH IN MM. 
WIDTH OF ME- 
DIAN LOBE. 
NO. OF SEGMENTS 
OF LOBE. 
PLEURJE DIS- 
TINCT AND IN- 
DISTINCT. 
5.3 
8 
2.9 
7-8 
6-7 
6.3 
9.8 
3.3 
8 
5-7 
5.1 
8 
2.9 
6-7 
4-6 
4.8 
7.3 
2 4 
6 
5-6 
5.2 
8.2 
2.5 
7-8 
4-7 
In all essential characteristics these specimens agree very well 
with the types already described from the Clinton Group at the 
Soldiers’ Home, near Dayton, Ohio. 
Encrinurus punctatus, Wahlenberg. 
Encrinurus punctatus was described by Hall from the Clinton 
Group of Indiana. It is cited by E. Billings from East Point and 
the Jumpers on Anticosti, but I have not had access to collections 
containing the same. At Collinsville, Alabama, a few pygidia were 
found. At Cumberland Gap, Tennessee, the pygidia are very num- 
erous and the glabellse occur in moderate numbers. Free cheeks are 
more rare. Encrinurus Thresheri , Foerste, is represented by py- 
