PLATE 84. 
1. 369. 4. Cyrtolites ornatus. (Pag. 308.) 
1 a. Lateral view of a cast of this species. 1 b. Profile of the same, looking into the aperture. 
1 c. Another specimen (a cast), where the volutions are contiguous. 
1 d. A specimen preserving the shell, from which the finer strise are removed. 
1 e. A portion of the surface of the shell, showing the sculpture. 1 f. Part of the same magnified. 
1 A transverse section of the shell. 
2. 249. 1 . Trocholites ammonius. (Pag* 309.) 
2 a. A small specimen, partially preserving the shell in some parts, and showing the septa in others. 
2 b. An enlarged portion of the surface, which is partially exfoliated, and slightly different from similar mag¬ 
nified parts of those in the Trenton limestone, where the shell is well preserved. 
2 c. Mould of a large specimen in the black slate. 
3. 370. 2. Trocholites planorbiformis. (Pag. 310.) 
3 a. Figure of a specimen nearly entire. 3 b. Dorsal view of the same. 
3 c. Ventral view of a fragment, preserving part of the two outer volutions, showing the concave ventral side, 
and the position of the siphuncle. 
3 c*. Section of the outer volution. 3 d. A portion of the surface magnified. 
3 e. A specimen crushed in a vertical direction, a part of the outer volution retaining its form. 
3/. Dorsal view of the same, showing the slightly arching septa upon the dorsal line, and a part of the outer 
chamber. 
