BRACHIOPODA. 



131 



No. 392. Strophomena planumbona. Hall. 

 Cincinnati Group, Waynesville, Ohio. 



No. 398. Leptaena sericea, Sow. 

 Cincinnati Group, Cincinnati, Ohio. 



No. 394. Orthis Eifleensis, Vern. 



300 species are known of this genus, restricted to the Palaeozoic. The 

 shell is transverseh' oblong; radiately striated or plaited; bi-convex; hinge- 

 line narrower than the shell. Middle Devonian, Eifle, Prussia. 



No. 395. Orthis laticosta, James. 



Mr. Meek considered this and the following- 

 species as varieties of Orthis biforota {Terebratu- 

 lites biforota), Schlotheim. Cincinnati Group, 

 Waynesville, Ohio. 



No. 396. Orthis lynx, Eichwald. 

 Cincinnati Group, Waynesville, Ohio. 



No. 397. Orthis occidentalis, Hall. 

 Cincinnati Group, Cincinnati, Ohio. 



No. 398. Orthis phcatella, Hall. 

 Cincinnati Group, Cincinnati, Ohio. 



No. 399. Orthis subquadrata, Hall. 

 Cincinnati Group, Waynesville, Ohio. 



No. 400. Orthis testudinaria, Dalman. 

 (Orthis emacerata. Hall). 

 Cincinnati Group, Cincinnati, Ohio. 



FAMILY PRODUCTID^. 



Shells concavo-convex; hinge-line straight; ventral valve convex; dorsal 

 concave. Extinct. 



