108 Cincinnati Society of Natural History. 
This species belongs to a group of Ostracoda whose generic 
relations are exceedingly doubtful. I follow Prof. T. Rupert 
Jones’ suggestion in referring this one to Pontocypris. My collec- 
tion contains at least six others from the Trenton and Cincinnati 
rocks of Kentucky, Tennessee, Illinois and Minnesota, having, 
apparently, close relations to the form here described. One is a 
form like Macrocypris vinet, Jones, and two of the others are more 
like species that are referred to Bythocypris. I should have liked 
to work them out at this time, but as it was impossible to do them 
justice in the limited time at my disposal, I have thought it best to 
postpone their publication till the next opportunity. 
Position and locality: The types of Pontocypris (2) ilinoisensis 
were collected at Savannah, Ill., where they occurred in strata of 
the Cincinnati Group associated with Primitia impressa and numer- 
ous small Aryozoa. 
CTENOBOLBINA, Nn. gen. 
Carapace small, elongate-sub-oval, strongly convex, the poste- 
rior two-fifths more or less decidedly bulbous or subglobular, and 
separated from the remainder by a deep, narrow sulcus extending 
in a gentle curve from the dorsal margin more than half the dis- 
tance across the valves toward the postero-ventral border. The 
anterior three-fifths often with another oblique but less impressed 
sulcus. Valves equal, the dorsal margin straight, hingement sim- 
ple, the ventral edge thick, and the true contact margins generally 
with a row of small spines on each side; in a lateral view both are 
concealed by a ‘‘frill” or flattened border, usually mistaken for 
the true contact edges. 
Surface generally granulose. 
Type, BEYRICHIA CILIATA, Emmons (BS. ¢umsfrons, Hall). late 
VIE, Pigs ta and 1.0. 
This genus is proposed for the reception of several new species 
and two others that have been described as Geyrichia. ‘The latter 
are B. ciliata, Emmons, and the closely related B. duryz, S. A. 
Miller, both from the Cincinnati Group. ‘They are not, however, 
congeneric with BL. kledent, McCoy’s type of Leyrichia. ‘True 
species of that genus have three lobes on each valve. ‘These are 
variously modified, but usually consist of a small central one, and 
two, more ridge-like and often united, enclosing it. The posterior 
