63 
Brachial valve much less convex than the pedicle, with the greatest 
convexity at the umbo; cardinal extremities flattened. Median fold low, 
broadly rounded, increasing in breadth rapidly towards the front. Plica- 
tions similar in number, character, and size to those of corresponding 
positions upon the opposite valve. 
The finer surface markings consist of minute radiating, papillose 
lines, covering the entire shell. 
Remarks . The average size of this species is much greater than the 
type of the specieB C. cyrtiniformis from the Chemung of Rockford, Iowa. 1 
The latter, a specimen of average size, has a width of 11 mm.; height of 
cardinal area of pedicle valve, 9 mm.; length of brachial valve, 12 mm., 
as against 21 mm., 12 mm., and 19 mm. for a medium-sized specimen from 
the Lake Minnewanka section. The pedicle valve of the latter has a more 
incurved cardinal area; the proportions of the delthyrium are similar, 
as well as the number of plications, on each side of the fold and sinus — 
that is, about 20 — for here the plications are simple; but as those on fold 
and sinus bifurcate the number here has increased on this enlarged shell to 
20 at the anterior edge, resulting in about 60 plications to a valve as against 
45 to 50 in the Iowan forms. The mature shell is slightly incurved at the 
front. This Minnewanka species differs thus from C. cyrtiniformis prin- 
cipally in its larger size, increased number of plications in the sinus, and 
especially in the more highly arched cardinal area. 
In size it is similar to the form noted by Whiteaves 2 from Hay river, 
Mackenzie; but this has only 29 or 30 plications upon each valve and is 
probably a distinct species. Cyrtia norwoodi Meek 8 is similar to our form 
in curvature of cardinal area but differs in its smaller size, narrower del- 
thyrium, narrower and shallower median sinus, and fewer plications (30 
to 40 instead of 60) . Spirifer disjundus animascensis Girty 4 with its char- 
acteristically twisted beak is usually a much broader shell with a vertical 
cardinal area, but even in the subquadrate forms, with length and breadth 
subequal, and with an arched cardinal area, the width of the cardinal area 
is 2$ to 3 times its Height, the delthyrium is almost as broad as high, and 
of plications also there are 20 to 25 upon each lateral slope and only 5 to 
10 in the sinus. Spirifer disjundus occidentals Whiteaves 8 is distinctly 
alate with coarse plications. 
This form is abundant upon the western flanks of mount Standly, 
whence the name. 
Locality and Horizon. The forms with which this variety is most 
nearly related occur in the Upper Devonian of North America. In the 
Minnewanka region this species occurs in the Upper Devonian of sections 
2-38 (C), 39 (r), 40 (r), 41 (C), 42 (R), 45 (?); 4-5 (r). 
1 Cyrtia cyrtiniformis (Hall and Whitfield), Twenty-third Rept. N.Y. State Col. Nat. Hist., 1872, p. 238, PI. 11, 
figs. 21-24. 
1 Spirifera cyrtinacformi s, Contr. to Can. Pal., 1, 1891, p. 222. 
* Spirifer utakensis, King’s U.S. Geol. Expl. 40tb Par. IV, 1877, p. 39, PI. 3, fig. 1. 
4 1900, U.S. Geol. Sury. , 20th Ann. Rept. , p. 48, PI. 4, figs. 1-10. 
* Contr. to Can. Pal., 1, 1891, p. 222. 
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