THE EURYPTERIDA OF NEW YORK 253 
E. newlini as here defined unquestionably belonged to the giants 
of the race and lagged little, if at all, behind E. scorpionis in size. 
Not less than three of the few specimens known indicate individuals of two 
feet or more in length. 
The species differed from E. scorpionis in being built still 
more compact and sturdy. This is shown in the relatively shorter and 
broader preabdomen, the shorter and especially broader postabdomen 
and the shorter, stouter and probably straight telson. The posterior 
contraction of the preabdomen is more abrupt and the outline of the pre- 
abdomen and carapace combined more broadly oval posteriorly. The 
walking legs are stouter and provided with longer spines; the swimming 
legs reach farther back (principally on account of the greater contraction 
of the preabdomen) and the postabdomen is notably broader. The cephalo- 
thorax has grown somewhat in proportion to the body, probably on account 
of the greater stoutness of the appendages for which it has to serve as basis 
of attachment. 
Eusarcus (?) cicerops Clarke 
Plate 36, figures 2-10 
Eurypterus? cicerops Clarke. N. Y. State Mus. Bul. 107. 1907. p. 307, 
pl.'s, fig. 10; also pl. s, fig. 7 
Description. The original description of this species which was based 
on a single specimen is: 
This diminutive head shield is remarkable for the extraordinary de- 
velopment of the compound eye lobes which are anterior and very prom- 
inent and though the shield has a diameter of only 4.5 mm, the ocellar 
mound is fully developed. So unusual is the aspect of this specimen that 
it can not be assigned to any of the other species here noted, and though 
entirely immature, it is given a distinctive designation. 
Later collections have furnished a few more specimens of like size 
exhibiting the same unusual characters as well as somewhat larger spec- 
imens which would indicate, if properly referred here, a remarkable change 
of characters in the ontogeny of this form. We shall first describe the type 
and then note the later changes. 
