A. Winchell on supposed New Cephalopods. [356] 7 
the chambers, while the position of the siphon admits of some 
doubt. 
Orthoceras occidentals, n. sp. 
Septate portion of shell more than 3f inches in length; greatest 
apical angle 8° to 12°; transverse section an ellipse whose minor 
axis is to the major as '37: •48=1*3; septa nearly transverse 
with a concavity equal to about one-fifth the greater diameter; 
interseptal space about one-fourth the same diameter. Siphon 
situated on the minor axis about midway between the center 
and periphery, constricted where it passes through the septa, 
about '06 in diameter in the chamber and '04 in the constriction. 
Localities. In the Marshall sandstone at Marshall and Moscow. 
This species differs from 0. Muensterianum deKon. (An. Foss., 
pi. xlviii, 1, 5), by its nearly transverse instead of very oblique 
septa. 
Orthoceras Barquianum, n. sp. 
Septate portion of shell more than 4J inches long; greater 
apical angle (i. e., the one formed by the sides which are not 
compressed) about 10°; transverse section an ellipse whose 
minor axis is to the greater as *35 : *50=1*43; septa somewhat 
oblique, making an angle of 8° or 10° with a transverse plane, 
most elevated near one extremity of the longer diameter ; 
amount of concavity and position of siphon unknown; distance 
between the septa about one-fifth the greater axis at the same 
place. No surface markings evident from an examination of 
casts. 
Locality. Near the light house at Pt. aux Barques in a hard 
bluish sandstone embraced in the shales of the Huron Group. 
(See Huron Group, (c.) of the preceding table.) 
This species may possibly prove identical with the preceding, 
but its apical angle is somewhat less, its septa more oblique, its 
section more excentric, and its geological position considerably 
lower. 
Orthoceras Marshallense, n. sp. 
Septate portion of shell more than 5*75 inches long; greater 
apical angle 6°; transverse section an ellipse whose axes are to 
each other as *36: *61 = 1*69; ratio of interseptum to greater 
axis *25 : *45=1*8; septa very concave, the concavity equaling 
*17; siphon on the minor axis, a little excentric. The cast gives 
no evidence of surface markings. 
Locality. In the Marshall sandstone at Marshall. 
This species is readily distinguished from its allies and asso¬ 
ciates by the great distance of the septa from each other, and 
the very gradual taper of the shell. 
Orthoceras clinocameratum, n. sp. 
The only specimen of this quite distinct form is only 1J inches 
iA 
