1883,] 239 
well marked, rising anteriorly in a low spine or tubercle, and again in a 
larger or more prominent one at its hinder end. A lower ridge crosses 
this at right angles, extending about half-way to the margin, and at the 
end of this are two semicircular ridges curving inward half-way to the 
median ridge, and sinking to the general level. In the hinder angle, be- 
tween this and the cross ridge, is a roundish mark which may indicate the 
place of the eye. Another elongated tubercle or short ridge lies between 
the anterior end of the median line and the margin. 
Surface marked with crowded, low tubercles, and with the delicate, 
‘scale-like sculpture of the genus. 
The fossil was found in the sandstone of the Catskill group at Meshop- 
pen, Penna., and is the property of R. D. Lacoe, Esq., of Pittston, to 
whose kindness I am indebted for the use of the specimen, and in whose 
honor I have named it. 
There is a species of Kurypterus described by Prof. Whitfield, in the 
forthcoming volume of the Paleontology of Ohio (New fossils from Ohio. 
Pamphlet), of which he says: 
“The cephalic shield is proportionately broader than that of 7. remipes 
or H. lacustris, and is more regularly rounded or arched on the anterior 
border, lacking that subquadrate form characteristic of those species.’’ 
This species, Hurypterus Briensis, from the hydraulic limestone of Put- 
in-Bay, Ohio, shows a manifest departure from the ordinary type of the 
head of Kurypterus, but the variation seems rather in the direction of 
Limulus or Huproops, than in that of Dolicocephala. As Prof. W. does 
not mention the size of his specimen, it is impossible to say how nearly 
the two approach in that respect. The horizon from which it comes in 
Ohio is the equivalent of the waterlime of New York, to which the genus 
Eurypterus is almost entirely confined. Two species are described from 
the Coal Measures, and one from the Devonian, of Pennsylvania. 
Stated Meeting, October 5, 1883. 
Present, 10 members. 
A photograph of Professor James Morgan Hart was pre- 
sented for insertion in the Album. 
Letters of acknowledgment were received from the Smith- 
sonian Institution (118), and the Sociedad Keonomica de Va- 
lencia, September 16. 
