Eurypterus (Anthraconectes) mazonensis Meek & Worthen 
Page 223 
1 Counterpart of type (holotype). Compare diagram text figure 51, p. 224. 
The specimen shows the general outline of the carapace, the form 
and position of the lateral eyes, portions of the legs and the impression 
of the dorsal side of the abdomen with the characteristic sculpture. 
Along the median line faint impressions of the opercular appendages 
are seen. The circular impressions apparently are muscle spots and 
probably paired. An outline sketch of this counterpart was given 
by Hall in 1884 [2d Geol. Surv. Pennsylvania, PPP, p. 25]. Natural 
size 
Horizon and locality. Lower Coal Measures. Mazon Creek, Grundy co., 
Til. 
Eurypterus (Onychopterus) kokomoensis Miller & Gurley 
Page 212 
See plate 25 
2 Ventral view of a specimen, showing the gill plates, the female opercular 
appendage and the posterior doublures of the segments as dark bands. 
Natural size 
Horizon and locality. Kokomo waterlime. Kokomo, Ind. 
Dolichopterus siluriceps nov. 
Page 273 
3 Holotype. Natural size 
Horizon and locality. Bertie waterlime. Buffalo, Erie co., N. Y. 
All figures are from photographs. The original of figure 1 is in the 
American Museum of Natural History (no. #5); that of figure 2 in 
the museum of Chicago University (no. 12909) and that of figure 3 
in Columbia University 
