464 WISCONSIN NATURAL HISTORY SURVEY 
in which they occur—due to crushing—have given rise to the belief 
that a number of species are represented. This, however, does not 
seem to be the case, as a comparison with 
the restoration will show (Fig. 3). 
appears to have been quite thin and easily 
distorted, in some cases one side being 
apparently pushed in until it became concave 
The shell 
and in contact with the opposite side. 
Named for the state of Wisconsin. 
Fic. 6.—Transverse Locality —Milwaukee Cement Quarry, Berthelet, 
Secon showing the mar- Wis! 
ginal position of the 
siphuncle in a crushed Gomphoceras whitfieldi, n. sp. 
specimen of Gomphoceras (Figs. 9, 10) 
calvini N. S. 
longitudinal section. Transverse section oval or 
circular. Conch rapidly and regularly enlarging 
to the point of greatest transverse section, which 
is about midway between the last septum and 
the aperture of the chamber of habitation, thence 
contracting more gradually to the aperture. 
Apical angle about 45°. 
Chamber of habitation wide, but very short; 
length in one specimen about 3.5°™ and greatest 
diameter about 6.25°™. Aperture large, oval or 
circular in the border of which there appears to 
be a sinus. 
Air-chambers regular, varying little in depth 
from the chamber of habitation to near the apex. 
Surface and siphuncle unknown. 
Length of two individuals about 13°™; 
greatest diameter of a crushed specimen about 
gm. 
This species differs from G. calvini in 
its more acute apical angle, its"symmetrical 
form, and its shorter chamber of habita- 
tion; from G. breviposticum and G. jusi- 
jorme in its greater size, relatively shorter 
chamber of habitation, and more obtuse 
apical angle. 
In the restoration the only points in 
Description.—Shell medium, sub-triangular in a 
rat 
Fic. 7.—Restoration in 
plaster of Gomphoceras cal- 
vini N. S. The shape of the 
apex and a portion of the 
apertural opening are some- 
what in doubt. 
