ARCTIC ORDOVICIAN AND SILURIAN CEPHALOPODS 273 
ited in the Palaeontologisk Museum at Kristiania. Original 
of fig. 2 on plate 13 of Holtedahl’s papery cited above. From 
the younger Dolomite series, in the Heclahook System of 
strata, corresponding to the Canadian of North America. 
From such a small fragment it is impossible to determine 
with confidence the generic relationship of this species, but it 
evidently belongs to the Tarphyceratidae, 
9. Kionoceras laqueatum (Hall) 
Orthoceras laqueatum Hall, Pal. New York, 1, 1847, p. 13, 
pi. 3, fig. 12. 
Type. — Apical angle about 9 degrees. Diameter at the top 
of the specimen estimated at 9 mm. In a letter Dr. Ruede- 
mann states regarding this specimen that ^^The Orthoceras 
laqueatum shows 11 vertical ribs on the visible half. Since 
that is not quite the entire half, I should judge there were 20 ribs 
on the shell. There is always one stria between two ribs’ 
Nothing is known of its interior structure. 
Locality and Horizon. — From some unknown locality in the 
Beekmantown division of the Canadian in New York state. 
Hall stated that ^Hhe position of the specimen is probably at 
the upper termination of this (Beekmantown) rock, and just 
at its passage into the succeeding limestone.’’ The type is 
numbered 12375 in the New York State Museum of Natural 
History at Albany, New York. 
Remarks. — The reference of this specimen to Kionoceras 
must be regarded as tentative. If Kionoceras arose from a 
multistriate ancestral Orthoceroid by the increased prominence 
of certain of the vertical striae, then Orthoceras laqueatum may 
be regarded as ancestral to typical Kionoceras. 
10. Kionoceras holtedahli Sp. nov. 
Orthoceras (Kionoceras?) sp. Holtedahl, Ordovician Fossils 
from Bear Island, 1918, p. 84, pi. 11, fig. 2. 
Judging from the figure published by Holtedahl, the apical 
angle of the conch is about 4.5 degrees, and the number of verti- 
