PLATE II. 
Pig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig- 
Legend. g. Umbonal scars. 
g'. Cardinal scars. 
1 Lateral scars, 
h. Central scars, 
c. Concrete centrals, 
z. External scars, 
b. Parietal scar, 
cr Crescent. 
p. Pedicle-gi oove. 
ps. Pedicle-sheath, 
d. Cardinal area, 
cc. Cardinal callosities, 
pi. Platform, 
s. Median septum, 
vs. Vascular sinuses. 
LINGULELLA, Salter. 
Page 55. 
Lingulella c^elata, Hall. 
1. A pedicle-valve, from which the shell is partially exfoliated; showing traces of the curved lateral 
and the central scars. X 2. 
2. A pedicle-valve, retaining most of the shell; showing the surface ornamentation and the open¬ 
ing of the foramen ; (a) longitudinal section, showing the'elevation of the beak ; (b) posterior 
elevation. X 2. 
3. A brachial valve; showing the central and lateral muscular impressions, and a very sharply de¬ 
fined scar (z) which, if not adventitious, may be homologous with the external scars in Obolella 
crasxa, or the terminal crescent scars in the Trimerellids. X 2. 
4. An incomplete cast of the same valve. X 2. 
Middle Cambrian. Near Troy, N. Y. 
Lingulella Dawsoni, Matthew. 
5. A cast of the interior of the pedicle-valve. X 3. 
St. John group. Portland, New Brunswick. 
Lingulella (?) paliformis, Hall 
6. A view from the dorsal side of both valves in normal juxtaposition ; showing the elevation of the 
cardinal area in the pedicle-valve, and its pedicle-slit, which by compression appears through 
the exfoliated apical portion of the brachial valve. X 2. 
Hamilton shales. Shurger’s Glen, Cayuga Lake, N. Y. 
7. A pedicle-valve, showing a faint slit along the position of the pedicle-groove. X 3. 
Hamilton shales. Pratt's Falls, Onondaga county, N. Y. 
8. A pedicle-valve, which has been Compressed along the filling of the pedicle-slit. X 3. 
Hamilton shales. Shurger's Glen, Cayuga Lake, N. Y. 
Lingulella Stoneana, Whitfield. 
(Lingulella aurora, var., Hall.) 
9. Dorsal view of a specimen. Natural size. 
10. The same, enlarged to three diameters; showing the characters of the cardinal area. 
11. An enlargement of the surface ; showing the concentric growth-lines crossed by undulating lamel- 
lose striae. 
Potsdam sandstone. In the upper, variegated magnesian layers, near Mazomanie, Wis. 
Lingulella aurora, Hull. 
12. A do real view of the specimen ; showing the high cardinal area, and its pedicle-groove. X 3. 
13. Another specimen, similarly enlarged. 
Potsdam sandstone. Near Mazomanie, Wisconsin. 
