THE EURYPTERIDA OF NEW YORK 425 
from the Frankfort beds at Schenectady and the still earlier Eusarcus 
linguatus from the Normanskill shale at Catskill also exhibit median 
extensions of the frontal margin of the carapace similar to the frontal 
lappet of E. vaningenti. 
The compound eyes in E. vaningeni appear to be placed con- 
siderably farther inward thanin E. scorpionis. We do not know, 
however, how much this difference is due to the fact that in E. van- 
ingeni the entire carapace is spread out, having been rather flat along 
the lateral margin, while in E. scorpionis the marginal parts were 
more or less vertical and bent under, thus bringing the submarginal lateral 
eyes on the margin of the compressed specimen. This latter condition 
is seen in the types of plates 29 and 30. 
NOTES ON ANTHRACONECTES 
When investigating this genus we were unable to locate the types 
of the Pennsylvania Carbonic species described by C. E. Hall and James 
Hall. These have been found in the Hall collection of Chicago University, 
whence we were able to borrow them through the courtesy of Professor 
Stuart Weller. For the purposes of completeness and facility of reference 
some notes on the species are here given: 
_ Eurypterus (Anthraconectes) mansfieldi C. E. Hall 
Dolichopterus-mansfieldi C. E. Hall. Am. Phil. Soc. Proc. Phila. 
1877. 16: 621 . 
Eurypterus mansfieldi James Hall. Sec. Pennsylvania Geol. Sur. PPP. 
1884. p. 32, pl. 4, fig. 1-8; pl. 5, fig. 1-11; pl. 6, fig. 1; pl. 7, fig. 1; pl. 8, fig. 1-3 
Eurypterus stylus James Hall. Jbid. p. 34, pl. 5, fig. 12-15 
Cf. E. potens James Hall. Jbid. p. 37, pl. 4, fig. 9, 10 
See text figures 43-47, page 220 . 
K. mansfieldi and E. stylus are associated in the ‘‘ shale 
immediately below ‘the Darlington cannel coal,: near Cannelton, Darling- 
ton township, Beaver county, Pennsylvania.’’ Hall cites [op. czt. p. 35] 
as the distinguishing feature of E. stylus and E. mansfieldi, 
1 Allegheny formation of the Pennsylvanian. 
