19I2. No. 9. ON SOME ORDOVICIAN FOSSILS FROM BOOTHIA FELIX ETC. a 
doceras (Endoceras) annulatum HarL, from the Trenton of New York, 
although as we are not acquainted with the interior it is impossible to 
determine the species exactly. 
Even less can be said respecting various other orthoceracones, gene- 
rally large and smooth. 
Gonioceras occidentale Hatt. 
Plate III. Fig. 1. 
1861. Gonioceras occidentalis Hatt. Rep. Geol. Survey Wisconsin p. 47. 
1897. Gonioceras occidentale CLARKE Geol. of Minnesota. Vol. III, part Il, p. 795. PI. 
EVIL, fig. 6. 
This form is represented by a number of specimens, although none 
of these shows the outer form in its entirety. We have however, an 
opportunity of observing both the outer limits of the shell, with its marked 
conical form, and the unique shape of the septa, from various natural 
longitudinal sections. There were also indications of the nature of the si- 
phuncle. The marked bending of the septa, particularly in the lateral 
expansions, makes it easy to separate this form from Gonioceras anceps Hart. 
The various specimens exhibit considerable variations in size, the 
greatest breadth measured being about 17 cm., although this does not 
represent the actual greatest breadth, since the front portion has been 
destroyed. 
Gonioceras occidentale occurs in the Trenton of Illinois and Wisconsin. 
The fossils collected are thus: 
Receptaculites oweni Har. 
Halvsites sp. 
Columnaria sp. 
Maclurea sp. 
Eurystomites sp. 
Actinoceras beloitense WHITFIELD. 
Actinoceras sp. (cf. tenuifilum Hatt). 
Gonioceras occidentale Hatt. 
In addition, there are certain undetermined forms of corals and 
cephalopoda. 
Regarding the question as to how far these fossils may be assumed 
to belong to one level, it is difficult to express any decided opinion, since 
