PLATE XHV—Continued. 
Meristella nasuta, Conrucl. 
See Plate 43. 
Fig. 13. An internal cast of a pedicle-valve ; showing the position of the teeth and the deep muscular im¬ 
pressions. 
Fig. 14. An internal cast of a small and very elongate pedicle-valve ; an unusual variation in fortn. 
Schoharie grit. Albany county, N. Y. 
Fig. 19. A pedicle-valve retaining the brachidium in a silicified and incrusted condition; showing the 
form of the cones and retaining in position the median septum of the brachial valve. 
Corniferous limestone. Williamsville, N. Y. 
Fig. 20. A similar specimen, the spirals being unincrusted and exposed by weathering. 
Fig. 21. The interior of an incomplete pedicle-valve ; showing dental plates and muscular impressions. 
Fig. 22. The interior of a brachial valve ; showing the subtriangular, medially concave hinge-plate, dental 
sockets, median septum and elongate adductor muscular area. 
Fig. 24. The hinge-plate enlarged ; showing the median depression, crural bases and supporting septum. 
X 3. 
Fig. 25. Cardinal view of an internal cast of conjoined valves; showing the impressions of the muscular 
scars, teeth and dental lamellje,'sockets and median septum. 
Corniferous limestone. Western Neio York. 
Fig. 26. An internal cast of the brachial valve. 
Schoharie grit. Schoharie, N. Y. 
Meristella lenta, Htill. 
An internal cast of the i,iedicle-vaU e; showing the stiong musculai’ scars and the generally de¬ 
pressed surface. X 2. 
A preparation, showing the form of the spiral cones resting in the pedicle-valve, with the median 
dorsal septum in position. 
An internal cast of the brachial valve, showing its convexity and the position of the median sep¬ 
tum. A portion of the filling of the pedicle-cavity of the opx^osite valve is also exjiosed. X 2. 
A longitudinal internal view, showing the jiosition and form of the looji and one of the sjural 
cones. Restored. 
Oriskany sandstone. Be Cewville, Ontario. 
Meristella Barrisi, Hall. 
See Plate 43. 
Figs. 27, 28. Two views of a iirejiaration, showing the form of one of the sjural cones. 
Fig. 29. An internal cast of conjoined valves ; showing the jiosilion of the median ,sex)tum and dental 
lamellffi. 
Fig. 30. An internal cast of the xiedicle-valve. 
Limestone of the Marcellus shale. Stafford, N. Y. 
Meristella Haskinsi, Hall. 
See Plate 43. 
Fig. 31. The interior of a jjeilicle-valve retaining the deltidial jdates, and showing the teeth and muscular 
scars. 
Hamilton group. Canandaigua Lake, N. Y. 
Fig. 15. 
Fig. 16. 
Fig. 17. 
Fig. 18. 
