PLATE LXXXIV—Continued. 
Strophonella costatula, sp. nov. 
Fig’S. 15, 16. Dorsal and profile views of the shell; showing the reversed convexity of the valves and the 
sharply rounded, irregularly dichotomizing plications. 
Niagara group. Louisville, Kentucky. 
liAFINESQUlNA ALTERNATA. Coiinid. 
Figs. 17. 18. Enlargements of umhonal portions of internal casts of the pedicle-valve, to show the filling of 
the pedicle-passag’e. In fig. 18, which represents the older shell, this filling is seen to be the 
smaller and is constricted at its base, evincing thus the tendency of the shell to close this pas¬ 
sage at its inner extremity. X 3. 
Hudson River group. Erratic blocks in western New York. 
Productella NAVICELLA, tLlll. 
See Plate 17. 
Fig. 19. A small pedicle-valve preserving the spines in a perfect condition and showing- the convergence 
of the cardinal spines. X 5. 
Hamilton group. Canandaigua Lake, Neio Yoik. 
Strophalosia Kockfordensis, .sp. nov. . 
See Plate 17a. 
Figs. 20, 21, 22. Ventral, dorsal and cardinal views of a sisecimen ; showing the general exteimal characters 
and the umbonal cicatrix 
Upper Devonian. Rockford, Iowa. 
Pleotambonites producta, sp. nov. 
Figs. 23, 24, 25. Cardinal, profile and front views of an internal cast of a pedicle-valve ; showing the form 
of the teeth and muscular impressions, the short hinge and the greatly produced anterior 
margin. 
Niagara dolomites. Yellow /Springs, Ohio. 
Hyattella congesta, Hull. 
See Plate 40. 
Figs 26-28. Doi’sal, front and profile views of one of the original specimens (Palsontology of New York, 
vol. II. pi. xxiii, figs. 1, f, g, i). 
Clinton group. Monroe county. New York. 
SpIRIFER LiEVIS, Hull. 
See Plate 38. 
Fig. 29. A portion of the cardinal region enlarged to show the peculiar structure of the deltarium, which 
bears a circular perforation with elevated margins, and is surrounded by an elongate, smooth 
area, at the edges of which the growth lines are sharply interrupted. X 3. 
Chemung group. Near Ithaca, New York. 
Seminula subquadrata, Hull. 
' See Plate 47. 
Figs. 30, 31. Dorsal and profile views of the original specimen. 
Kaskasia limestone. Chester, Illinois. 
Cliothyris Eoy.ssii, Leveille. 
Fig. 32. The interior of a brachial valve ; showing the form of the hinge-plate. 
Coal Measures. Tournai, Belgium. 
Ath" s conoentrica, von Bucli. 
Fig. 33. An enlargement of the hinge-^ ite ; showing its form, tripartite division, and apical perforation. 
' Middle Devonian. Ferques, Brittany. 
