300 
IOWA ACADEMY OF SCIENCE 
The high obliquity of the segments of this fragmentary specimen 
makes its reference to Stokes’ species rather doubtful, while the highly 
silicified condition of the interior makes even generic determination 
uncertain. 
Occurrence and Locality : The specimen is in the University 
collection and was found in the Niagaran, Hopkinton, Iowa. 
Geological Laboratory, 
State University op Iowa. 
EXPLANATION OF PLATE XXXIII. 
(All Figures Natural Size.) 
Hukonia vertebralis Stokes. 
Fig. 1. Two large segments showing unusual obliquity for this species. 
Huronia obliqua Stokes. 
Fig. 2. A series of nine segments, the terminal ones imperfect. The 
greatest obliquity is at right angles to the side shown. Note that 
the concave surface of each segment is smoother than the convex. 
Huronia hopkintonensis sp. nov. 
Fig. 3. The type specimen. Greatest obliquity not shown. 
Huronia turbinata Stokes. 
Fig. 4. Portion of the siphuncle showing the obliquity of the segments, 
also a fragment of the turned up part of the septum adhering to 
the concave surface of the upper segment. The smoothness of Ihe 
concave part is not well brought out in the photograph. 
EXPLANATION OF PLATE XXXIV. 
(All Figures Natural Size.) 
Discosorus (?) BicoNoiDEus sp. nov. 
Pig. 1. The paratype. A large incomplete siphuncle showing the 
obliquity of the segments, the amount of their separation, nnd 
their thinning toward the anterior end. 
Fig. 2. A more complete siphuncle of a smaller individual, the holo- 
type, showing tapering toward each end. 
Actiistoceras cf. RiCHARDsoNi Stokes. 
Fig. 3. View of a fragmentary specimen showing its nummuloidal 
character and the septal remnants attached to the posterior sur- 
faces of the segments. Note the high obliquity of the segments. 
Huronia subcyeindrica sp. nov. 
Fig. 4. The type specimen. Shows the nearly cylindrical character of 
the segments, the low anterior ring, and the narrow septal groove. 
The view is at right angles to the greatest obliquity. 
Huronia vertebralis Stokes. 
Fig. 5. A typical specimen showing a slight amount of tapering, seg- 
ments with subparallel sides, and rounded evenly-inflated anterior 
rings. 
