OF DENISON UNIVERSITY. 
93 
same time. Tubercles and posterior parts of the glabella are unknown. 
Length of glabella, 3.5 mm, including the rim, 4.7 mm; distance 
between edges at junction of facial sutures with the anterior outline of 
the head, 3.7 mm. 
Locality and position. Brown’s Quarry. Clinton Group. 
Genus ILL^NUS, Dalman. 
IV. Ill/enus Daytonensis, Hall and Whitfield. 
(Plate Wll, Figs. 6, 7.) 
At Brown’s Quarry a head of this species was found by Prof. W. 
S. Hoskinson, of Wittenberg College, which presents the movable 
cheeks and the rostrum in position. Unfortunately the postero-lateral 
regions of the movable cheeks are broken off. The character of the 
rostrum may be easily seen from the figure. The facial sutures extend 
along the anterior border of the head, of which the rostrum appears 
a continuation. The movable cheeks become attenuated anteriorly 
and take a twist which gives their surface a direction in 'the same plane 
with the rostrum, against which their tips are accurately fitted. 
Locality and position. Soldier’s Home Quarries, Brown’s Quarry, 
Ludlow Falls (movable cheek and part of a glabella), Fair Haven (a 
pygidium), Fauver’s Quarry (a pygidium). Clinton Group. 
In Ohio this species is the most widely distributed and most char- 
acteristic form of the Clinton Group. It would be interesting to 
know if this is also the case in Wisconsin and Illinois, where similar 
specimens are said to occur (Ohio Pal. Vol. H, p. 120). 
I have seen this species in the collections of the Central Park 
Museum, labeled Hamburg, Illinois. 
V. Ill^nus Madison I an us, Whitfield. 
(Plate VHI, Fig^. 8, 9, 10, loa.) 
I 
Since the publication of the last peeper little has been added to the 
knowledge of this species. In that paper two specimens were de- 
scribed. The first pigidium from Huffman’s Quarry was very convex 
and had the anterior edge arching decidedly forwards. The other 
specimen from Stolz’s Quarry was much flatter, broader and less arch- 
ing anteriorly. At Brown’s Quarry numerous pygidia are found, which 
