Lorraine Faunas of New York and Quebec 295 
served in the Victoria Memorial Museum, at Ottawa, Canada, by 
the Geological Survey of Canada. No. 8428. 
This species probably is closely related to Modiolodon truncatus, 
Hall, and Modiolodon suhovalis, Ulrich. At least it presents a 
similar outline, but there is no evidence of the presence of teeth 
near the beak. 
28. Psiloconcha subovalis, Ulrich 
{Plate II, Figs. 15 A, B) 
The specimens here described resemble closely the specimen of 
Psiloconcha subovalis figured by Ulrich from the Maysville divi- 
sion of the Cincinnatian section at Morrow, Ohio. The anterior 
margin is rather oblique as it rounds into the basal margin, and 
the hinge-line posterior to the beak is straight for about a dis- 
tance of 21 mm. in a shell 35 mm. long and 17 mm. high, resulting 
in a rather high shell considering the group of species so far in- 
cluded in the genus. The convexity of the single valve is about 
3 mm. Compared with the figures of Psiloconcha subovalis the beak 
is broader and more protuberant, the junction of the umbonal 
ridge with the cardinal slope is more angular along the distance 
from the beak halfway toward the posterior margin, the faint 
mesial depression or flattening is more distinct, and anteriorly 
the beak is defined more strongly by an oblique angulation almost 
as strong, although much shorter than the umbonal ridge; more- 
over, the anterior margin is more regularly rounded. At the 
beak the shell appears compressed, as though the shell had for- 
merly been more inflated along the umbonal areas. 
The specimens here figured were obtained along the Riviere 
des Hurons, near St. Jean Baptiste, October, 1872, by Thomas 
Curry, and are associated in the same block with Clidophorus 
praevolutus and a pygidium of Isotelus. Preserved by the Geo- 
logical Survey of Canada in the Victoria Memorial Museum at 
Ottawa. No. 8408. 
Shells indistinguishable from Psiloconcha inornata, Ulrich, oc- 
cur half a mile south of the railroad station at St. Hilaire, in a 
ditch along the road; and a closely similar species occurs a mile 
and a half northwest of Vars, at a crossing of two country roads. 
