ARCTIC ORDOVICIAN AND SILURIAN CEPHALOPODS 265 
annulations indicate corresponding markings on the exterior of 
the shell is unknown. 
Locality and Horizon. — Found at Point Levis, Quebec, in the 
Levis representative of the Canadian formation. Type, num- 
bered 819, in the collections of the Geological Survey of Canada. 
Remarks.- — The preceding description of the type of Eremo- 
ceras syphax differs necessarily from those previously presented, 
since only the dorsal side was exposed when the specimen was 
studied by Billings and Hyatt. Recently, however, the writer 
removed all of the surrounding matrix, thus exposing for the 
first time the large siphuncle. What formerly had been regarded 
as the siphuncle apparently was a slight discoloration along the 
median line of the dorsal side, and this had been emphasized 
by vertical scratches made in an attempt to learn more of the 
supposed siphuncle. 
4. Ellesmeroceras scheii Gen et. Sp. nov. 
Plate XXVII, figs, 3 A, B, C; Plate XXXIII, fig. 3 
Conch straight along the ventral side and presumably straight 
also along the dorsal side as far as may be determined from the 
specimen at hand. Apical angle small, probably about 8 degrees 
in a dorso-ventral direction. Conch compressed laterally. At 
the base of the living chamber the dorso-ventral diameter is 
estimated at 12 mm.; the lateral diameter is 10.5 mm. 
The number of camerae in a length equal to the dorso-ventral 
diameter of the conch at the top of the series of camerae being 
counted is 10. Since the uppermost camera has about the 
same length as the camerae immediately beneath, it is not cer- 
tain that the conch is mature. The sutures of the septa slope 
from the siphuncle along the median line of the ventral side 
downward toward the dorsal side, curving in a slightly sigmoid 
manner. Along the middle of the lateral sides of the conch the 
sutures form an angle of about 80 degrees with the vertical 
axis; toward the siphuncle the sutures rise more rapidly and 
toward the dorsal side of the conch they descend more rapidly 
than along the middle of the lateral sides. 
