A CERA TA—MERO STOMA TA . 



405 



Large, length of cephalothorax less than half the width ; eyes 

 of medium size, oblique and con- 

 nected by a distinct arched line or 

 fold; abdomen of convex segments, 

 which slope outwards into nearly 

 flat pleurae with rounded anterior 

 ends ; telson broad and flat ; length 

 of type no mm., width 49 mm. 

 (Type of genus.) 



Potosi limestone of Missouri. 



VIII. EuRYPTERUs Dekay. 

 Body elongate and narrow, of- 

 ten of great size ; cephalothorax 

 one fifth or one sixth of the whole 

 length including the telson; de- 

 pressed-convex, subcjuadrate in 

 outline, with the anterior angles 

 rounded and the posterior margin 

 slightly concave. Entire margin 

 bordered by a narrow, marginal 

 furrow; eyes reniform, situated 

 somewhat in front of the middle of 

 t]:e cephalothorax ; ocelli close to the median line ; mouth a ventral 



p-io. 1704. Strabops ihatcheri, 

 the type specimen, X ^- (After 

 Beecher. ) 



d • e 



Fig. 1705. a-c, Eurypte7'us inaria, a, an entire individual, 5.5 mm. long; b, a 

 specimen 8 mm. long; c, an incomplete individual 20 mm. long, ventral aspect; 

 d, e, Hughmilleria shnzvangunk ; cephala, d, nat. size ; «' X 4- (After Clarke.) 



