PLATE XVI.— Continued. 
Ecjomphalus (Phanerotinus) Eboracensis. 
Page 61. 
Fig-. 19. The upper surface of an entire specimen showing the general form. 
Fig. 20. The periphery of the spire, showing the cicatrices. 
Figs. 21-23. The peripheral sides of three other specimens which consist only of parts of the outer volution. 
All of these show the constrictions of the tube and the cicatrices left by the removal of frag¬ 
ments ; figs. 21 and 22 show the scars extending entirely through the shell. 
PORCELLIA HERTZERI. 
Page 126. 
Fig. 24. Lateral view of the specimen, natural size. 
Goniatites PLEBEIFORMIS. 
Page 448. 
Fig-s. 25, 26. Lateral and profile views of an individual preserving the chamber of habitation : the inner 
volutions having been dissolved and removed. 
PORCELLIA NAIS. 
Page 127,. 
Fig-. 27. Apertural view of the typical specimen, which has been obliquely crushed, showing the form and 
< characters of the shell and the surface-markings. 
Fig. 28. The back of the specimen, showing the breadth of the outer volution, the retral bending of the sur¬ 
face striae across the dorsum, and the oblique, elongate nodes of the lateral angles. 
