Eurypterus lacustris Harlan 
Page 173 . 
See plates 9, 11-13 
t Ventral view of a female, showing well the ventral marginal shield of the 
cephalothorax, the three pairs of walking legs in their natural position, 
the balancing legs and swimming legs. The metastoma shows the 
cleft of the anterior margin indicating its origin from fusion of two 
plates. The first and second sternites are pushed together and the 
genital appendages broken off. The other sternites show the trans- 
verse middle line of scales and the median longitudinal suture. The 
last postabdominal segment exhibits the two longitudinal rows of 
scales of the dorsal side. Natural size 
Horizon and locality. Bertie waterlime. Buffalo Cement Company's 
quarry, Buffalo 
Photograph. Original in the State Museum 
460 
