264 NEW YORK STATE MUSEUM 
postabdominal segments are furnished with distinct epimera that increase 
in width with each succeeding member, and are prolonged into short spurs, 
except on the last segment where they are produced into long, rounded 
lobes. The posterior doublure is wide, amounting to nearly one half the 
width of the first segment. 
The telson is narrow and long, apparently little shorter than the post-_ 
abdomen. It contracts rapidly for a short distance from the anterior 
end, then it continues slender, or increases again slightly to the point 
which is abruptly rounded. The section is triangular. The dorsal surface 
is flat or slightly convex, the ventral produced into a flat-topped carina. 
The edges are sharp and marked by oblique incisions which, toward the 
extremity, grow into sharp teeth. 
The preoral appendages of the cephalothorax have not been seen. 
The first three pairs of postoral appendages form a series of remarkably 
stout walking legs that increase in length posteriorly and decrease very 
little in width distally. They consist of short, ringlike segments, all of which, 
except the three basal ones, bear a pair of extremely long, curved spines 
[pl. 45, fig. 3]. The terminal spine or claw also is distinguished by its great 
length. It is flanked by the almost equally long spines of the last segment. 
The fourth limb, which has been known hitherto by its basal portion only, 
displays quite as peculiar characters as thé last limb. In length it is 
intermediate between the third walking leg and the much elongated swim- 
ming leg, begins rather slender and becomes gradually wider distally. 
Though it terminates in a very long and strong claw, thus having the 
appearance of a walking leg, this claw is not flanked by the two like spines 
on the last segment as in other eurypterids, but by two broad bract- 
like lobes. Tracing these legs proximally, the impressions of further bract- 
lke appendages are seen on the inner side [pl. 45, fig. 2, 3], in the places 
where in the preceding legs the long paired spines are found. Since 
the opposite sides of the same leg show these bractlike lobes, it is ap- 
parent that they represent a modification of the spines of the preceding 
limbs. 
