PLATE XXXIX. 
(Figs. 1-3 copies; 4-9, 39-41 by 11. P. Whitfield; 10-14, 19-27. 29-31, 34-36, 42 by G. B. Simpson; 15-18, 28, 32, 33, 37, 
38 by E. Emmons.) 
Genus VERNEUILIA, gen. nov. 
Page 58. 
Vekneuilia cheiropteryx, tie Venieuil. 
Figs. 1-3. Three views; showing the slight asymmetry of the shell, and the trisulcate surface of each 
valve. (After pe Verneuil.) 
Middle Devonian. Paffrath, Gminany. 
Genus AMBOCCELIA, Haul. 
Page 54. 
See Plate 29. 
Ambocoelia umbonata, Conrad. 
Figs. 4-6. Three views of an average example ; showing the great convexity of the pedicle-valve, its me¬ 
dian gi'oove, and the depressed-convex, mai-ginally concave brachial valve. 
Fig. 7. The interior of the pedicle-valve; showing the elevated umbo, the thickened, unsupported teeth 
and the partial filling of the delthyrium. X 3. 
Fig. 8. The interior of the brachial valve ; showing the low cardinal pi’ocess, elevated crural plates, and 
the four adductor scars. X 3. 
Fig. 9. A preparation, showing the volutions of the spiral coils. X 3. 
Hamilton shales. Western JSew York. 
Amboccelia planoconvexa, Shuinard. 
Figs. 10-12. Views of a rather large example ; showing the general form and contour of the valves. 
Fig. 14. Posterior view of the same specimen ; showing the cardinal areas, the imperfectly developed 
deltidial plates and chilidium X 3. 
Coal Measures. Springfield, Illinois. 
Fig. 13. A small individual. 
Fig. 15. Enlargement of the surface of the same specimen ; showing the short spinules. X 5. 
Coal Measures. Manhattan, Kansas. 
AmbOCOSLIA SPINOSA, sp. BOV. 
Fig. 16. The exteiior of a brachial valve. 
Fig. 17. An enlargement of the surface ; showing the narrow, elongate deiiressions which were probably 
the bases of superficial spines. X 6- 
Fig. 18. Internal cast of the same specimen ; showing the impression of the dental sockets and crural 
plates, and the faint adductor scars. 
Hamilton group. Livonia Salt Shaft, N. Y. 
Genus METAPLASIA, gen. nov. 
Page 56. 
Metaplasia pyxidata, Hall. 
Fig. 19. Interior of a brachial valve; showing the articulating appai-atus, adductor scars and vascular 
sinuses about the muscular area and over the marginal regions. X 2. 
Fig. 20. Posterior view of the same valve; showing the width of the cardinal area, elevation of the cardi¬ 
nal process and socket-walls, and the linguate extension of the median sinus on the anterior 
margin. X 2. 
Fig. 21. Internal cast of the pedicle-valve ; showing the median fold, and the impressions of divergent, 
probably vascular sinuses extending forward from the pedicle-cavity. X 2. 
Fig. 22. Interior of a portion of the pedicle-valve ; showing the narrow cardinal area, thickened teeth and 
deep muscular scar, X 2. 
Oriskany sandstone. Cayuga, OntaHo. 
Genus SPIRIFERINA, iyOrbigny. 
Page 51. 
See Plates 29, 36. 
' Spiriferina, sp. ? 
Fig. 23. Interior of a portion of the brachial valve ; showing the articulating apparatus and the divergent 
muscular ridges in the bottom of the valve. X 3. 
Fig. 24. A portion of the interior of the pedicle-valve ; showing a highly developed delthyrial callosity 
uniting the dental lamellie and supjioi-ted by a median septum. X 2. 
Chester limestone. Caldwell county, Kentucky. 
