BRACHIOPODA. 
223 
ORTHOSTROPH I A, Hall. 1883. 
VI. Group of Orthis strophomenoides, Hall. 
*[?]0. fasciata, Hall . . Niagara. 
* 0. Ualli, Safford . Lower Helderberg. 
* 0. strophomen¬ 
oides, Hall . Lower Helderberg. 
PLATYSTROPHIA, King. 1850. 
VII. Group of Orthis biforata, Schlotheim. 
* 0. biforata, Schlotheim . Chazy—Clinton. 
* 0. acutilirata, Conrad . Hudson River. 
* 0. crassa, James . Hudson River. 
* 0. laticosta, Meek Hudson River. 
* 0. lynx, von Eichwald . Hudson River. 
HETERORTHIS 
(nom. propos). 
VIII. Group of Orthis Clytie, Hall. 
* 0. Clytie, Hall . Trenton. 
BILOBITES, Linne. 1775. 
IX. Group of Orthis biloba, Linne. 
* 0. biloba, Linne . Niagara. 
* 0. varica, Conrad . Lower Helderberg. 
DALMANELLA 
(nom. propos). 
X. Group of Orthis testudinaria, Dalman. 
* 0. Electra, Billings . Quebec. 
*[?]0. Evadne, Billings . Quebec. 
