PLATE XXXIII—Continued. 
MYTILARCA CAR1NATA. 
Page 259.'. 
See Plate 32. 
Fig. 8. An'enlargement of the cardinal portion of fig. 19, plate 32, as obtained from an impression, showing 
more clearly the hinge characters. 
Chemung group. Near Elmira, N. Y. 
Modiola (Mytilops) pr^ecedens. 
Page 267. 
Fig. 9. A small left valve denuded of the striae. 
Figs. 10, 11. Cardinal views of two specimens with the valves partly opened. 
Fig. 12. A small right valve. 
Fig. 13. A left valve of medium size, preserving the surface striae. 
Fig. 14. An elongate rig-ht valve, showing the surface characters. 
Chemung group. Olean, N. Y. 
Fig. 15. A right valve, probably of this species but showing no surface stria. 
Chemung group. Smethport, Pa. 
Fig. 16. The cardinal view of a specimen, with both valves strongly striate. 
Fig. 17. A large broad specimen preserving the surface markings. 
Fig. IS. The anterior view of an example showing nearly equal convexity of both valves. 
Chemung group. Olean, N. Y.» 
Mytilarca simplex. 
Page 261. 
Fig. 19. A large right valve, showing varices of growth. 
Fig-. 21. A smaller left valve. The beak should be directed slightly to the left to give the proper expres¬ 
sion to the figure. 
Chemung group. Smethport, Pa. 
Mytilarca gibbosa. 
Page 262. 
See Plate 87. 
Fig. 20. The left valve described. Another figure is given on plate 87, fig. 7. 
Chemung group. Napoli, Cattaraugus Co., N. Y. 
Mytilarca lata. 
Page 262. 
Fig. 22. A right valve showing- the broad form of the shell. 
Chemung group. Randolph, N. Y. 
Modiola (Mytilops) metella. 
Page 268. 
See Plate 87. 
Figs. 23, 24. Two right valves showing the general form of the shell. A figure of another specimen is given 
on plate 87 in the same position as the figures of M. prcBcedens on the present plate for a better 
comparison. 
Chemung group. Chautauqua Co., N. Y. 
