THE EURYPTERIDA OF NEW YORK 251 
as rows of fine teeth. The segments forming the arm or pole of the swimming 
legs are rather short, ringlike and broad with intricate articulations, none of 
which however is well preserved. The seventh and eighth segments form a 
much lengthened but little broadened blade; the seventh segment is about 
one and one half times as long as wide and occupies nearly one third of 
the length of the arm beyond the coxa. The proximal extremity is deeply 
notched for the articulation with the preceding segment; the lobelike plate, 
marked off from the inner distal margin by a suture, is rounded and occupies 
half the width of the segment. The palette is a long subelliptical body, 
twice as long as wide; its distal extremity slightly convex, the inner nearly 
straight. It carries at its distal extremity a nearly circular claw of rela- 
tively great size (one fourth the length of the palette) so snugly fitted in 
a corresponding notch that it is discerned with difficulty. The edges of 
the blade are furnished all around with small serrae. 
The metastoma has not been seen. 
Genital appendages. The only trace of a genital appendage seen 
is a small oval area which suggests an immature female appendage. 
Ornamentation. The preservation of most of the material is such 
that the substance of the integument is a finely puckered carbonaceous 
film obscuring all former surface ornamentation. In the smallest specimen 
the impression of the postabdomen shows small elongate elliptic scales 
of the character of thosein E. scorpionis [pl. 39]. On the stern- 
ites and the carapace of the same specimen traces of small circular mark- 
ings are also observable, suggesting that on the whole, the ornamentation 
of this form was little different from that of E. scorpionis. 
Horizon and localities. All representatives of this species have come 
from the Kokomo waterlime horizon at Kokomo, Indiana. 
Remarks. A survey of the specimens figured '! shows that they form 
' A fifth still smaller specimen is in the National Museum. ‘This is so poorly pre- 
served that it is not capable of furnishing positive data. It is, however, of interest in 
suggesting that the telson was considerably longer than indicated by the other speci- 
mens and probably also curved as in the other species of Eusarcus [see pl. 36, fig. 11]. 
