84 
Igoceras sp. 
Description. Shell broadly conical, expanding very rapidly from the 
subcentral apex. Surface bearing about ten prominent plications. Con- 
centric growth lines numerous, becoming somewhat lamellose anteriorly. 
The diameter of the aperture is 20 mm., whereas the height of the specimen 
is 7 mm. ; this great difference between height and diameter is due to the 
vertical crushing the specimen has suffered, though it was probably 
originally somewhat broader than high. 
Remarks. This somewhat resembles I. quincyense (McChesney) of 
the Burlington of the Mississippi valley, but is a much smaller shell . 
Locality and H orizon. In the Minnewanka region in the Pennsylvanian 
of section 2 a-14 (R). 
Genus, Conularia Miller 
Conularia alternistriata n. sp. 
Plate IV, figure 11 a, b 
Description. Shell quadrangular, tapering very gradually. Each of 
the four sides is slightly convex, nearly flat. A prominent longitudinal 
furrow is present on each angle. Sides crossed by sharply elevated, 
closely arranged transverse strise which have smooth, even tops and sides. 
These arch forward in an obtuse angle at the apex of which they break, 
their ends alternating on each side of the sharply elevated longitudinal line 
that traverses the middle of each side (hence the specific name). Very seldom 
are these transverse strise continuous across the median longitudinal line. 
There are five of these striae in a space of 2 mm. Faint longitudinal lines 
(about 20 across one side) further ornament the spaces between the trans- 
verse striae, but do not cross them. The single specimen in our collection 
is 10 mm. long with a diameter of 4 mm. at one end and of mm. at the 
other. Since the specimen is broken it is impossible to judge of the adult size. 
Remarks. In C. subulata Hall from the Middle Mississippian (St. 
Louis) of the Mississippi valley 1 the median longitudinal line does not inter- 
rupt the course of the transverse striae. 
Locality and Horizon. In the Minnewanka region in the Mississippian 
of section 2-25 (R). 
Phylum, ARTHROPODA 
Class, CRUSTACEA 
Subclass, Trilobita 
Genus, Proetus Steimnger 
Proetus perocddens Hall and Whitfield 
1877. Proetus perocddens Hall and Whitfield, U.S. Geol. Expl. 40th Par., 
vol. 4, p. 262, PI. 4, figs. 28-32; Girty, 1899, U.S. Geol. Surv., 
Mon. 32, pt. 2, p. 576, PL 71, figs. 14 a-b. 
Remarks. Our two specimens, an imperfect cephalon and an imper- 
fect pygidium, agree very closely with the type descriptions and figures 
except that our form has a more pustulose glabella, Hall and Whitfield’s 
description noting only a few granules at the base of the glabella. 
Locality and Horizon. In the Mississippian of Utah and Yellowstone 
National park. In the Minnewanka region in the Mississippian of section 
2-23 (R), -25 (R). 
1 12th Rept. Geol. Surv. , Indiana, p. 372, PI. 31, fig. 3. 
