248 
AUG. F. FOERSTE 
nence of the oblique lateral ribs toward the ventro-lateral angles 
in the figure of the Eurystomites published by Dr. Holtedahl 
(Holtedahl, Plate II, fig. 1), this Nautiloid is a Ptectoceras related 
to such Black River forms as Plectoceras undatum (Conrad) and 
Ptectoceras halli (Foord). The siphuncle of the specimen identi- 
fied as Actinoceras heloitense (Whitfield) (Holtedahl, Plate IV, 
fig. 2) appears to be too small for typical forms of that species. 
The form figured as Actinoceras sp. cf. tenuifilum(B.Si\\) (Holte- 
dahl, Plate III, fig. 2) was kindly loaned to the present writer by 
Dr. Holtedahl, and is figured on Plate XXVI of the present paper. 
It has shorter camerae and a smaller siphuncle than Actinoceras 
tenuifilum, and probably belongs to a new species of which more 
material is needed to discriminate it satisfactorily from other 
forms. 
In the specimen figured by Holtedahl as Endoceras {Cyclendo- 
ceras) annulatum Hall (Holtedahl, Plate IV, fig. 1), the annula- 
tions are much stronger and the number of camerae in a length 
equal to the diameter of the conch is much less than in typical 
forms of that species. Moreover, it does not present the strong 
downward flexure of The annulations on the ventral side of the 
conch characteristic of typical Cyclendoceras. Its * general 
appearance is more like that of a Dawsonoceras^ but, in the 
absence of any knowledge of its siphuncle, it is impossible to 
state positively that it could not be a Cyclendoceras, 
In addition Dr. Holtedahl loaned also a number of Actino- 
ceroids, a part of which are here figured and described in the hope 
that further material may be collected elucidating these forms. 
One of these is named Actinoceras amundseni in honor of Captain 
Roald Amundsen, the leader of the expedition. The material 
forwarded includes also a peculiar orthocone, flattened on one 
side, for which the new term Leurorthoceras hanseni is proposed 
in honor of Lieutenant Godfred Hansen, the geologist of the 
expedition and the second in command. It is regarded as a 
new genus. The Actinoceroids and the species of Leurorthoceras 
just mentioned are regarded as of Black River age. 
In 1913 the same Videnskabs-selskabet of Kristiania published 
Dr. Holtedahks paper on ^^The Cambro-Ordovician Beds of 
