TUBICOLAR ANNELIDA. 
17 
The following forms are here regarded as representing various stages of 
development of what appears to be a single species of the genus Cornulites. 
The figures to which names are here applied are those most nearly resembling 
the illustrations of the several species as given by the authors, and not as 
determined by the writer. 
SPIRO R BIS, Lamarck. 1801. 
Spirorbis Cincinnatensis. 
PLATE CXV, FIGS. 1, 2. 
?Spirorbis Oinvinnatensis, Miller and Dyer. Jour. Ciii. Soc. Nat. Hist., vol. i, p. 38, pi. i, tig. 13. 1878. 
Hudson River group. Cincinnati, Ohio. 
OllTONIA, Nicholson. 1872. 
Ortonia minor. 
PLATE CXV, FIG. 3; ANO PLATE CXVI A FIGS. 19,20. 
Ortonia minor, Nicholson. Geological Magazine, vol. x, p. .76, pi. iv, tig. 2a. 1873. 
Hudson River group. Cincinnati, Ohio. 
Ortonia conica. 
PLATE CXV, FIG. 27 ; AND PLATE CXVI A, FIGS. 15, 10. 
Ortonia conica, Nicholson. Geological Magazine, vol. ix, p. 447, tig. 1. 1872, 
Hudson River group. Cincinnati, Ohio. 
CONCH ICO LITES, Nicholson. 1872. 
Conchicolites corrugatus. 
PLATE CXV, FIG. 27 ; and PLATE CXVI a, FIGS. 17, 18. 
Conchicolites corrugatns, Nicholson. Geological Magazine, vol. x, p. 55, pi. iv, tig. 3. 1873. 
Hudson River group. Cincinnati, Ohio. 
TE N T A C U L IT E S, Schlotheim. 1820. 
Tentaculites Sterlingensis. 
PLATE CXV, FIGS. 5-7, 32. 
Tentaculites Sterlingensis, Meek and Worthen. Pi-oc. Acad. Nat. Sci., p. 255. 1865. 
Hudson River group. Cincinnati, Ohio. 
