DEVONIAN FAUNAS. 353 
specimens, having the strong, concentric lines of growth and the obso- 
lete, radiating plications, seem to be essentially like the shell from 
New York which is known as Megalanteris ovalis (Hall). This shell 
from New York, however, has never exhibited the brachidium, so that 
it is-not really known to be a member of the genus to which it has 
been referred. A specimen from New Jersey retains the brachidium, 
however, and it is essentially the same as that of Beachia suessana as 
known from Cumberland, Maryland. This would indicate either that 
M. ovalis and B. suessana are synonymous, representing extreme varia- 
tions in the surface markings, or that they are two distinct species, 
both belonging to the genus Beachia. 
SPIRIFER ARENOSUS (Con.). 
Plate XLVIIL., Fig. 5. 
1859. Spirifer arenosus Hall, Pal. N. Y., vol. IIL, p. 425, pl. 98, 
figs. 1-8, pl. 99, figs. 1-10, pl. 100, figs. 1-8. 
Description——sShell large, subsemi-circular, subsemi-elliptical or 
subelliptical in outline; hinge-line equaling the greatest width of the 
shell or a little shorter; cardinal extremities angular or rounded. 
Pedicle valve strongly convex or gibbous on the umbo; the surface 
somewhat flattened toward the cardinal angles and curving regularly 
toward the front, depressed along the median line in a shallow, 
rounded, more or less ill-defined mesial sinus; beak prominent, some- 
s 
what incurved; cardinal area becoming rather wide in old shells, con- 
cave, sharply defined, reaching to the extremities of the hinge-line; 
delthyrium broadly triangular. Internally the muscular impressions 
are large and deep. Brachial valve with its greatest convexity near 
the middle; mesial fold low, rounded, more or less ill-defined. Sur- 
face of both valves marked by from fifteen to twenty depressed, 
rounded plications on each lateral slope. The fold and sinus are also 
similarly plicated, but on these portions of the shell the plications 
increase in number by bifurcation, those on the sides being simple. 
The surface is also marked by fine, concentric strie and by stronger, 
-imbricating lines of growth. 
