Notes on Cincinnatian Fossil Types 
311 
The chief characteristics of Lingula hrookvillensis are its medium 
size, rather elongate quadrangular outline, and the thinness of the 
valves excepting where thickened by callosities. The horizon ap^ 
pears to be near the base of the Richmond group, probably within 
the Arnheim member. 
19. Trematis crassipunctata, Ulrich 
{Plate VI, Fig. 6) 
1889. Trematis crassipunctata Ulrich, Amer. GeoL, k, p. 22: 3, p. 378, Fig. 7 
The types of Trematis crassipunctata, including the specimen 
figured by Ulrich, belong to the collection of Prof. Charles Schuchert,. 
of Yale University. The species was described from the Fairmount 
member of the Maysville group at Cincinnati, Ohio. 
The tjrpe figured by Ulrich is 15.5 mm. in length and 16 mm. 
in width. It is preserved in clay shale, and at present is rather 
flattened, but originally it probably had a convexity of 2.5 mm. 
About 90 radiating striations may be counted at the margin of the 
shell, but of these only about 50 are present within a radius of 5 
mm. from the beak. Along the median parts of the shell anteriorly 
5 interspaces, between the radiating striations, occur in a width of 1.7 
mm., and the almost rectangular pits here number 5 in a length of 1.6 
mm. Along the antero-lateral margins the pits are larger, numbering 
5 in a width of 2.8 mm., and 5 in a length of 2,4 mm. In this type 
specimen, the radiating striations and pits may be traced to the beak. 
In the second specimen, accompanying the figured specimen,, 
and labelled as coming from the vicinity of the Lookout House at 
Cincinnati, Ohio, there are no pits within a distance of 4 mm. from 
the beak. At first the interspaces between the pits are relatively 
wide, but become narrow anteriorly, especially beyond 8 mm. 
from the beak. Along the antero-lateral parts of the shell there 
are 5 pits in a width of 2 mm., and 5 pits in a length of 1.6 mm. 
This species is distinguished chiefly by the large size of the pits 
between the radiating striae, and by their strongly quadrangular 
appearance. 
20. Trematis fragilis, Ulrich 
{Plate III, Fig 12 ) 
1873. Trematis punctostriata Hall and Whitfield, Pal. Ohio, 2, p. 70, Plate 1, Fig. 9 
1910. Trematis fragilis Foerste, Bull. Sci. Lab. Denison University 16, p. 38, Plate 
5, Fig. 2) 
The shell here figured is numbered 102 in the James collection at 
Chicago University. It was found at Cincinnati, Ohio, but the 
