76 TRANSACTIONS OF THE ROYAL CANADIAN INSTITUTE. [VOL. XI 
OOCERAS, sp. indet. 
A cast of the chamber of habitation and of a portion of the septate 
region of a small, laterally compressed, rapidly tapering cyrtoceracone. 
The two specimens doubtfully belong to the same species. 
The body chamber of one specimen is 19 mm. long. At the pos- 
terior end, it measures 12.5 by 10 mm. ‘Transverse section ovate, 
with the narrow part on convex side of shell. Contracts rapidly towards 
aperture. Nature of aperture not indicated. 
The second fragment is 20 mm. long. Section elliptical or slightly 
ovate. Anterior diameter 12 mm. (dorso-ventral) and 9 mm. (lateral). 
Posterior diameters 8.5 and 7 mm. respectively. Medium curved. 
Exogastric. Septa 1.6 mm apart. Sutures with a slight lateral lobe 
and dorsal and ventral saddles. 
Locality—Limestone rapids, Severn river, District of Patricia, Ontario. 
Horizon—Silurian. 
No. 336 S. Royal Ontario Museum of Palaeontology. 
OOCERAS (?), sp. nov. 
Plate III, Figure 4; Plate VI, Figures 3 and 8. 
Two fragments probably referable to the same species; they indicate 
a medium sized, laterally compressed, slowly tapering, exogastic cyrto- 
cone. The cross section is elliptical rather than ovate. The smaller 
specimen is 33 mm. long and shows 14 camere in that distance. The 
anterior diameter is 25 mm. (dorso-ventral) and 20 mm. (lateral). The 
posterior diameter is 20mm. by 16mm. On the convex side the anterior 
septa are 3 mm. apart and the posterior septa are scarcely 2 mm. apart. 
The sutures are fairly even, with perhaps a slight lateral lobe. The 
siphuncle is of fair size, nummuloidal, and marginal in position. 
The second specimen is larger and shows part of the body chamber, 
which is at least 43 mm. long with a diameter of 31 mm. The septa 
average 3 mm. apart. The siphuncle is nummuloidal, marginal, and 10 
mm.in diameter. There is some evidence of a contraction of the living 
chamber towards the aperture. 
These two specimens indicate shells of similar structure, and they are 
possibly but not certainly of the same species. Both show characters 
pointing to the genus Ooceras as emended by Foord, or to Maelonoceras 
of Hyatt. In the absence of any striking specific peculiarity it would 
be ill advised to establish a species on material of such imperfect preser- 
vation. 
Locality—Limestone rapids, Severn river, District of Patricia, Ontario. 
Horizon—Silurian. 
No. 330 S. Royal Ontario Museum of Palaeontology. 
