Lorraine Faunas of New York and Quebec 265 
under a good magnifier, and even then in some cases quite ob- 
scure. Visceral space very little, the valves being so closely 
drawn together, translucent. Interior not observed. 
Breadth of a full-sized specimen, f inch; length, ^ inch. 
Position and locality. Cincinnati Group, about 350 feet above 
low watermark of the Ohio River, at Cincinnati. 
Collected by U. P. James. 
10. Rafinesquina mucronata, sp. nov. 
{Plate 11, Figs. 7 A, B) 
Shell small, the length about three-fifths of the width, but vary- 
ing in different individuals. Usually slightly extended along the 
hinge-line beyond the middle width of the shell so as to produce a 
small mucronate projection; but some individuals have rectangu- 
lar posterolateral outlines. Usually obliquely wrinkled along the 
hinge-line. Radiating striae fine, with every fourth one dis- 
tinctly more conspicuous along the middle and anterior parts of 
the valve; usually the stria found along the median line of the 
shell is more conspicuous than any of the remainder. Pedicel 
valve only moderately convex, the brachial valve slightly con- 
cave, almost flat. 
Locality. Along the Nicolet River, southwest of Ste. Monique, 
from 80 to 870 feet below the lowest strata containing Stro- 
phomena planumbona. As type forms, those occurring between 80 
and 530 feet below the lowest Strophomena planumbona horizon 
are selected. Here they occur associated with forms resembling 
Whiteavesia pholadiformis, Modiolopsis concentrica, and Catazyga 
erratica. In the underlying beds, Proetus becomes common. It 
occurs in the Proetus zone also at Chambly. 
The specimens here figured were obtained west of Vars, at a 
locality found by going about a mile west from the station, along 
the railroad, and then a third of a mile northward along the road. 
Here it also is associated with Catazyga. It occurs also a mile 
farther north, at the first cross roads, and also along the railroad 
about a mile northwest of Hawthorne station. 
The species appears closely allied to Rafinesquina squamula, 
James, from the Fairmount beds in the lower part of the Mays- 
ville division of the Cincinnatian strata in Ohio. The latter. 
