Pterygotus (Erettopterus) globiceps nov. 
Page 374 
1 Nepionic stage showing the enormous size of the lateral eyes, the position 
of the ocelli and the small number of segments. x 30 
2 Another larval specimen showing slightly different form of carapace, 
thickened rim of eyes and small number of segments of tapering ab- 
domen. X 30 
An older (neanic) stage in which the abdomen has assumed the pro- 
portion and composition of the adult stage. A broad thickened 
rim surrounds the eyes. x 12 
4 Carapace of a young individual showing somewhat different characters, 
apparently due to compression in longitudinal direction. x 15 
Fragment of carapace of young individual, showing the smooth cornea 
of the eyes partly separated from the facettae. x 5 
Well preserved carapace. Type of the species. x 3 
Largest carapace observed. Shows the lateral eye, somewhat distorted 
by oblique compression(indicated by the wrinkles) and the ocelli. 
On the antelateral corner a fragment of the marginal shield of the 
ventral side with traces of ornamentation is seen. Natural size 
8 Tergite showing antero-lateral lobes and ornamentation. x 3 
-g Second sternite with genital appendage of young female. x 3 
to Swimming leg. Natural size 
Oo 
qn 
IO 
Pterygotus (Erettopterus) sp. 
11 Portion of a telson showing fine bristles on the margin. Natural size 
12 Telson of young individual. x 3 
The figures 8, 10, 11 are referred with doubt to this species. 
Pterygotus? sp. 
13 Problematical fossil, possibly the female genital appendage of a Ptery- 
gotus [cf. similar appendage of Pterygotus anglicus, Huxley 
and Salter, pl. 3, fig.4, 5, 7]. 
Horizon and locality. Shawangunk grit. Otisville, N. Y. 
The originals are the State Museum 
604 
