282 
Aug, F. Foerste 
stream from the railroad bridge, about a mile east of Pulaski, 
and this is regarded as the type locality for both species. 
In the Paleontology of New York, vol. I, 1847, on plate 81, Hall 
presents various figures of Modiolojpsis modiolaris. Of these. 
Figs, la, h, represent specimens collected at Rome, while Ic, d, and 
e were drawn from specimens secured at the type locality, at 
Pulaski. Regarding Fig. la. Hall states: ^^This is one of the 
most perfect forms, and the one to which Mr. Conrad applied the 
name modiolarisd^ In one respect his published figure, however, 
differs from the specimens collected at the type locality: the angle 
between the cardinal and basal margins is greater. This is shown 
by the following table, giving the measurements for three speci- 
mens collected at Pulaski, one from half a mile east of Worth- 
ville (plate III, Fig. I), and for Fig. la, left valve, as published by 
Hall on plate 81 of the publication cited. (See Figs. 1, 2, on 
Plate V.) Measurements are given in millimeters. 
LOCALITY 
GREATEST 
LENGTH 
POSTERIOR 
HEIGHT 
HEIGHT 
AT 
BEAK 
ANTERIOR 
MARGIN 
FROM 
BEAK 
CONVEXITY 
OF SINGLE 
VALVE 
ANGLE 
BETWEEN 
CARDINAL 
AND BASAL 
MARGINS 
BETWEEN 
CARDINAL 
AND 
POSTERIOR 
MARGINS 
Pulaski 
57.0 
26.0 
20.0 
10.5 
4 
ir 
44° 
Pulaski 
59.0 
27.0 
20.0 
10.0 
4 
11° 
38° 
Pulaski 
63.5 
30.5 
25.0 
12.0 
4 
o 
O 
42° 
Worthville 
i 70.0 
32.0 
23.5 
10.0 
4 
12° 
39° 
Fig. la, PI. 81. 
69.0 
33.0 
22.0 
11.0 
19° 
42° 
Shell obliquely oblong. The cardinal margin posterior to the 
beak nearly straight, rounding gradually into the oblique posterior 
margin. Anterior to the beak, the cardinal margin is deflected 
downward, and then rounds into the strongly curved anterior 
margin of the shell. Basal margin straight along that part of 
the shell which lies directly opposite the straight cardinal margin; 
rising gradually toward the curved anterior margin, and more 
rapidly toward the posterior margin, which is most curved at the 
posterior extremity of the umbonal ridge. Umbonal ridge most 
strongly defined on the cardinal side and within about 10 or 15 
mm. from the beak, almost disappearing into the general con- 
vexity of the shell posteriorly. Mesial sinus practically obsolete, 
although occasional specimens show a very faint indication of the 
same accompanied by a scarcely perceptible concavity of the 
