222 NEW YORK STATE MUSEUM 
the eurypterids which in the Upper Siluric were the lords of the sea, were 
now put largely on the defensive. Fritsch has contended [1904, p. 77] 
that Glyptoscorpius is but an eurypterid and that the supposed combs are 
merely long fringes at the posterior margins of abdominal segments, and if 
this is correct then this genus may represent an extreme development of 
Anthraconectes. 
The third feature which the Carbonic species have in common is the’ 
exaggeration of the development of the epimeral pieces of the abdominal 
segments, well seen in the figure of E. mazonensis on the left 
side [text fig. 50]. E. mansfieldi shows the same features very clearly 
[text fig. 44] and E. approximatus possessed long 
and recurving epimera on the preabdominal segments (the 
postabdominal segments are not satisfactorily preserved 
in the single type). These epimeral pieces are pro- 
duced into strong recurving spines [text fig. 49] and 
the character is hence entirely in line with the spin- 
osity of the surface, increasing the gerontic aspect of 
these species. 
Another important distinctive character is the lack 
Figure 49 Euryp- Of differentiation between the first three pairs of endo- 
etal are gnathites and the last pair. This is especially distinct in 
Clarke. Copy of E. mansfieldi [text fig. 43]. Finally these species of 
ote es Anthraconectes were fresh or brackish-water animals while 
the true Eurypteri were marine. 
Even if the characters of the opercular appendage noted by Meek 
and Worthen should not warrant the recognition of this subgenus, the 
features mentioned which are common to the majority of the Carbonic 
Eurypteri are fully competent to verify their suspicion that ‘‘other charac- 
ters will be found showing it to belong to a distinct subgenus—if not 
indeed to an entirely distinct genus from Eurypterus proper.’’ It is on 
the sum of these characters that we would base the subgenus Anthra- 
conectes. 
