234 
AUG. F. FOERSTE 
is slig'htly angular. On the dorsal side of the conch, the down- 
ward curvature of the sutures is more moderately and more 
evenly concave. The lateral outlines of the conch diverge at 
an angle of 11°. No growth lines are preserved on the exterior 
of the shell. 
Locality and Horizon. — Pauquette Rapids, in the Ottawa River, 
Canada ; in the Leray member of the Black River. 
Remarks. — The specimen here described is numbered 1281 in 
Victoria Memorial Museum, at Ottawa, Canada, and is there 
found among the types of Orthoceras hastatum Billings, from 
which it is here separated as a distinct species. 
The specimen here described as Tripteroceras pauquettense 
probably is distinct generically from typical Tripteroceras. The 
latter probably contains only species with moderately expanded 
siphuncular segments, species with nummuloidal segments prob- 
ably being referable to a distinct genus. 
32. CHARACTOCERAS GEN. NOV. 
Genotype: Trochoceras (?) baeri Meek and Worthen. Proc. Acad. Nat. 
Sci. Philadelphia, 1865, p. 263; Meek, Geol. Surv. Ohio, Pal., 
1, 1873, p. 157, pi. 13, fig. 9. 
Conch nautiloid, depressed dorso-ventrally, the dorsal side 
being impressed at contact with the ventral side of the preceding 
volution. The transverse striae indicate that the margin of the 
aperture curved increasingly downward from the dorsal side of 
the conch toward its ventral side, the hyponomic sinus being 
broad and relatively deep, but not abrupt. The sutures of the 
septa curve moderately downward laterally, rising farther on the 
ventral than on the dorsal side. The siphuncle is located near 
the ventral side, but not in contact with the latter. The seg- 
ments of the siphuncle are somewhat between subfusiform and 
elongate elliptical in outline. 
The conch of Uranoceras Hyatt is compressed laterally, and 
there is no dorsal furrow, although adjacent volutions often are 
so close as to touch each other. The sutures of the septa are 
more sinuous laterally, at later stages of growth. The siphuncle 
is only slightly ventrad of the center of the conch, and the down- 
ward curvature of the septal necks is distinct. The form of the 
segments is elongate cylindrico-elliptical. The genotype is 
Uranoceras urannm Barrande, from the Silurian of Bohemia. 
