PLATE XCIY. 
Gomphoceras abrtjptum. 
Page 339. 
Fig. 1. A fragment which has been extremely compressed, showing a portion of the chamber of habitation, 
with the septate part of the shell. A constriction of the tube near the middle of the outer 
chamber is not represented in the figure. The specimen is covered with a branching, tubular 
Bryozoan. Hamilton group. Cazenovia, IV. Y. 
Gomphoceras raphantis. 
Page 347. 
Fig. 2 A fragment preserving several air-chambers and a small portion of the grand chamber, showing the 
position of the plane of greatest transverse section. Hamilton group. Pratt's Falls, Onon¬ 
daga county, N. Y. 
Fig. 3. Septum of the preceding, showing the transverse section of the tube. The siphuncle near the ven¬ 
tral margin of the septum, and surrounded by an areola, is not represented. 
Fig. 4. An individual somewhat compressed, but showing the attenuation of the apex and the depth of the 
. air-chambers. The septate portion continues to the point of greatest transverse section at the 
base of the chamber of habitation, but is not shown in the figure, owing to being covered by 
the remains of the macerated shell. Hamilton group. Pratt's Falls, Onondaga county, N. Y. 
Fig. 5. Ventral side of a specimen referred to this species on account of the position of the plane of greatest 
transverse section and the depth of the air-chambers. The specimen is much compressed, but 
shows the elements of the siphuncle, as exposed from weathering, and the sinus in the margin 
of the aperture, corresponding to the small aperture. The margin of the aperture is entire, 
and not broken, as represented. Hamilton group. Cazenovia, N. Y. 
Fig. 10. A fragment preserving the same form and proportions shown in specimen fig. 2. The siphuncle, as 
shown at the ventral margin of the septa, is not represented. Hamilton group. Pratt's Falls, 
Onondaga county, IV. Y. 
Gomphoceras oviforme. 
Page 344. 
See Plates 45, 46. 
Fig. 6. Ventral view of the chamber of habitation, showing the small aperture, the constriction of the tube, 
and the fossa of the crenulated zone at the base. The furrows of the crenulations, extending 
over the zone and the greater portion of the grand chamber, are not represented. Goniatite 
limestone. Schoharie, IV. Y. 
Fig. 7. The last septum of another specimen, showing the size and position of the siphuncle, and the trans¬ 
verse section of the tube. Goniatite limestone. Schoharie, N. Y. 
Gomphoceras Ajax. 
Page 350. 
Fig. 8. A portion of the chamber of habitation and three air-chambers, showing the size of the tube and the 
features of this portion. The striae and furrows of the crenulations, as continued over the walls 
of the air-chambers in the specimen, are not shown in the figure. Portage group. Penn 
Yan, N. Y. 
Gomphoceras pingue. 
Page 346. 
See Plate 95. 
Fig. 9. A fragment showing the ventricose form of the shell and the curvature of the sides of the chamber 
of habitation toward the aperture. Hamilton group. Cazenovia, IV. Y. 
