144 Tne American Geologist. March, 12m 
scribed from this horizon, in Europe and America. The only 
Devonian type hitherto noted from America is the Protolimu- 
lus eriensis of H. S. Williams (sp.), from the Chemung 
group in Erie county, Pennsylvania. It is therefore of some 
importance to be able to add a second distinct form, belonging 
to another genus, and occurring at nearly the same geological 
horizon. 
The species here described, and referred to Prestwichia, 
was discovered in the sandstones of the Upper Chemung group, 
near Ackley Station, Warren county, Pennsylvania, by Mr. F. 
A. Randall of Union City, Pa. Three examples of the cephalo- 
thorax are represented in the collection, varying somewhat in 
size, but clearly belonging to the same species. Since the ab- 
domen in this form is unknown, the principal diagnostic char- 
acter between the genera Prestwichia and Belinuris can not be 
applied, yet the size and general expression of the cephalo- 
thorax agree more closely with the known species of Prest- 
wichia. On this account, the present type is referred to the 
latter genus with little hesitation. 
The writer takes pleasure in dedicating this species to his 
lifelong friend, Mr. F. A. Randall, in recognition of his im- 
portant services on the geology and paleontology of Warren 
county, Pennsylvania. 
Prestwichia randalli, n. sp. (Figure 1.) 
Cephalothorax crescentic, convex, with a slight depression in front; 
width more than twice the length; anterior border somewhat subquad- 
rate in outline; posterior margin concave; genal angles broad, angular, 
apparently not extending into spines. 
The glabellar region is marked by a conical elevation along the mid- 
dle, extending about two-thirds the length of the cephalothorax, and 
terminating at the apex in a distinct node. There is a ridge on each 
side of this node, extending outward, then curving backward nearly 
parallel to the axial cone, and joining the posterior margin. The spaces 
enclosed between the conical axis and the outer ridges are each marked 
by five, low, rounded nodes, which may be considered as lobes of the 
glabella and are thus indicative of its segmental nature as well as of a 
corresponding number of paired appendages on the ventral side. 
The eyes seem to have been situated on rather prominent elevations 
of the ridges limiting the glabellar area. Their location is represented 
by the exfoliated spots in the figure here given. Another specimen, not 
illustrated, shows the position of the eyes more closely, though from 
the coarseness of the rock no definite details can be observed. 
