PLATE XVI. 
(Figures 1-16,18-22, 24-30, 32-44 by E. P. Whitfield ; 17, 31 by F. B. Meek ; 23 copy.) 
Legend. D. Deltidium, pedicle-valve. j. Cardinal process. 
C. Deltidium, 'brachial valve. a. Anterior adductors, 
st. Cardinal tubes. a'. Posterior adductors, 
t. Teeth. r. Anterior diductors. 
b. Dental sockets. r-C Posterior diductors. 
s. Septum. v. Brachial ridges. 
Genus CHONETES, Fischer de Waldheim. 
(See Plate XVb.) 
Page 303. 
Chonetes cornuta, Hall. 
Fig. 1. A view of the pedicle-valve. X 2. 
Clinton group. Sodus Bay, N. Y. 
Chonetes setigera, Hall. 
Fig. 2. A view of the pedicle-valve. X 2. 
Waverly group. Penfield, Ohio. 
Fig. 5. Pedicle-valve of a larger specimen with finer striae. X 2. 
Fig. 19. An enlargement of the surface striae of this specimen. 
Marcellus shales. Near Caledonia, N. Y. 
Chonetes scitula, Hall. 
(?)Fig. 3. A pedicle-valve, with somewhat more circular outline and longer cardinal spines than usual. X 2. 
Fig. 4. A view of the brachial valve; showing the cardinal area and deltidium. 
Fig. 27. The interior of a brachial valve; showing the structure of the cardinal process and the faint 
brachial ridges. X 2. 
Fig. 32. The interior of the pedicle-valve; showing the cardinal area and teeth. X 2. 
Hamilton group. Canandaigua Lake, N. Y. 
Fig. 40. An enlargement of the cardinal portion of the valves ; showing the hollow spines and the curving 
course of the spine-tubes through the substance of the cardinal area of the pedicle-valve. X 8. 
Hamilton group. Western New York. 
Fig. 44. An internal cast of the pedicle-valve, retaining the filling of the spine-tubes and showing their 
convergence toward the beak before reaching the upper margin of the area. X 8. 
Chemung group. Cattaraugus county, N. Y. 
Chonetes mucronata, Hall. 
Fig. 6. A pedicle-valve with very coarse plications and apparently destitute of spines. X 2. 
Fig. 7. A pedicle-valve with long, extremely divergent spines. X 2. 
Marcellus shales. West Avon, N. Y. 
Chonetes acutiradiata, Hall. 
Fig. 8. The pedicle-valve. 
Corniferous limestone. WilliamsviUe, N. Y. 
Chonetes Logani, Norwood and Pratten, var. Aurora. Hall. 
Fig. 9. Pedicle-valve, enlarged to show the fine concentric striae. X 3.. 
Fig. 18. An enlargement of the surface. 
Tnlly limestone. Tully, N. Y. 
