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. vaningeni.
The compound eyes in E. vaningeni appear to be placed considerably farther inward than in E. scorpionis. We do not know, however, how much this difference is due to the fact that in E. vaningeni 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. Ibid. p. 34, pl. 5, fig. 12–15
Cf. E. potens James Hall. Ibid. p. 37, pl. 4, fig. 9, 10
See text figures 43–47, page 220
E. mansfieldi and E. stylus are associated in the "shale immediately below the Darlington cannel coal,[1] near Cannelton, Darlington township, Beaver county, Pennsylvania." Hall cites [op. cit. p. 35] as the distinguishing feature of E. stylus and E. mansfieldi
- ↑ Allegheny formation of the Pennsylvanian.
