ARCTIC ORDOVICIAN AND SILURIAN CEPHALOPODS 271 
is nearly central, one side being 4.5 mm. from the nearest wall 
of the conch while the other side is 5 mm. distant from the 
opposite wall. Within each camera the enclosed segment of 
the siphuncle appears to become narrower in a downward direc- 
tion, curving slightly inward so as to present slightly concave 
vertical outlines. Apparently the lower margin of each segment 
of the siphuncle invaginates into the top of the septal neck next 
beneath. Apparently also the surface of the shell is slightly 
annulated, the crests of the annulations coinciding with mid- 
height of the earner ae. 
Locality and Horizon. — Collected 1 kilometer west of Norsk- 
havna, or 1.4 kilometers north-north-west of the northern margin 
of South Harbor on Bear Island, July 1918, by Olaf Holtedahl. 
In the Palaeontologisk Museum, Kristiania, Norway. Original 
of Fig. 1 on plate 11 of Holtedahrs paper on the Paleozoic Systems 
of Bear Island. From the younger dolomite series, in the Hecla- 
hook System of strata, corresponding to the Canadian of North 
America. 
Remarks. — The specimen from Bear Island is too poorly 
preserved for exact determination, but its annulation, though 
slight, and its large sub central siphuncle with segments narrow- 
ing in a downward direction suggest affinities vj\i\iProtocycloceras 
lamarcki. At least the resemblance is sufficient to suggest the 
Canadian age of the enclosing strata on Bear Island. The 
original identification of these Bear Island strata as Canadian 
was based by Holtedahl on the association in the same strata 
of such characteristic genera as Calathium, Archaeoscyphia, and 
Piloceras. The Bear Island Calathium resembles Calathium 
pannosum Billings, an Ozarkian species from Point Levis, 
Quebec, and the Piloceras is closely related to Piloceras explana- 
tor Whitfield from the Beekmantown member of the Canadian 
in Vermont and New York. Archaeoscyphia is listed from the 
Canadian of the Mingan Islands, in Canada. 
