202 
AUG. F. FOERSTE 
septa rise 2.5 mm. higher on the right side than on the left. This 
indicates that the sutures of the septa are oblique, and that the 
siphuncle probably was located naarer the left side of the speci- 
men, somewhere in that part which has weathered away. On the 
right side of the specimen the septa are more closely crowded, 
suggesting that, notwithstanding the general orthoconic aspect 
of the specimen, it may have been somewhat cyrtoconic in struc- 
ture. There is no evidence that this single specimen is even con- 
generic with the small apical ends of orthoconic shells figured by 
Hall on the same plate (Fig. 11a). 
3. ELLESMEREOCERAS FOERSTE 
Genotype: Ellesmereoceras scheii Foerste. Journ. Sci. Lab., Denison 
Univ., vol. 19, p. 265, pi. 27, fig^s. 3 A, B, C.; pi. 33, fig. 3, 1921 
The genus Ellesmereoceras was founded on the belief that there 
was a group of Endoceroids in which endocones we.re absent. If 
eventually it should be proved that endocones were present, the 
value of this generic term would be questionable. In most of the 
species having the general appearance of Ellesmereoceras the 
vertical outlines of the septal necks are distinctly concave, but 
there is no clear evidence of the invagination of the lower part of 
these necks into the upper part of the neck next beneath, as in 
typical Endoceras. The camerae usually are closely crowded. 
This type of structure appears to be characteristic of Canadian 
strata, but may have originated in Ozarkian times. 
Holochoanitic cephalopods with endocones are known to be 
present in the Ozarkian, and are under investigation by Dr. E. 
0. Ulrich. 
4. PROTOCYCLOCERAS HYATT 
Genotype: Orthoceras lamarcki Billings. Canadian Nat., vol. 4, 1859, 
p, 362; Foerste, Journ. Sci. Lab. Denison Univ., vol. 19, 1921, 
p. 268, pi. 33, figs. 7 A-D 
Protocycloceras was established by Hyatt to include annulated 
orthoceracones and cyrtoceracones without longitudinal ridges 
but with a large siphuncle. 
Ruedemann has shown® that in Orthoceras lamarcki, the geno- 
type, the septal necks have a length equal to that of one camera, 
and that within the camerae their vertical outlines are concave. 
He has also figured a similar structure in Protocycloceras whit- 
® Ruedemann, R., op, cit., p. 440. 
