91 
The Jurassic fauna 1 in the Fernie formation at Minnewanka lake, 
Alberta, also contains Sonninines and a pelecypod, Oxytoma mcconnelli 
Whiteaves 2 * , similar to the Silver Lake Oxytoma submcconnelli n. sp. ; this 
is probably, in part at least, another Middle Inferior Oolite or Bajocian 8 
fauna. Other faunas of similar age, i.e. Middle Inferior Oolite, but con- 
taining Stepheoceratidse and Sphaeroceratidae, are found in the lower part 
of the Yakoun formation at Skidegate inlet, at the base of the Fernie 
formation on Sheep creek, Alberta, and in the Fernie formation on Kan- 
anaskis river and at other localities in western Alberta. The Fernie forma- 
tion of western Alberta and eastern British Columbia contains also other 
faunas, ranging as high as the middle Upper Jurassic 4 5 ; one of these higher 
faunas, represented by an ammonite species from Kananaskis river, is 
similar in composition and age to the Kosmoceratidae-bearing upper Yakoun 
fauna of Skidegate inlet. 
SYSTEMATIC DESCRIPTIONS 
Ctenostreon gikshanensis n. sp. 
{Gikshan, an Indian tribe) 
Plate XIX, figures 3, 4 
A somewhat oblique, moderately convex species, having a short 
hinge-margin, a small anterior, and a large triangular, posterior ear. 
Commonly seven, rarely six or eight, narrow, somewhat flexuous, curved 
ribs, separated by wide, shallow interspaces. Somewhat rugose surface. 
No tubular spines known. 
Height 105 mm.; length 100 mm.; thickness 29 mm. 
This species has fewer ribs than the European species Ctenostreon 
pecteniformis (Schlotheim) 6 * . It is proportionate longer, has narrower 
ribs with wider interspaces, and commonly has one less rib than Ctenostreon 
electra (d’Orbigny) 6 of the French Jurassic; in Ct. electra the ribs near 
the umbo are narrow, but before midgrowth they begin to broaden and 
flatten and continue so to full growth. 
Horizon and Locality . From talus of middle sedimentary division 
of the Hazelton group, exposed in a cliff about 1 mile southeast of Silver 
lake, Hudson Bay mountain, B.C. 
Types: Victoria Memorial Museum ; holotype, Cat. No. 7700; paratype, 
Cat. No. 7700a. 
1 Whiteaves, J. F.: Geol. Surv., Canada, Contr. Can. Pal., vol. I, pt. 2, pp. 163-172. 
* Whiteaves, J. F.: Geol. Surv., Canada, Contr. Can. Pal., vol. I, pt. 2, p. 166, PI. 23, figs. 1 a, b. 
Whiteaves, J. F.: Geol. Surv., Canada, Mes. Foss., vol. I, pt. 4, p. 300. 
* McLearn, F. H.: Geol. Surv., Canada, Sum. Rept. 1922, pt. B, p. 6. 
4 McLearn, F. H.: Geol. Surv., Canada, Sum. Rept. 1922, pt. B, p. 6. 
5 As figured and described by Morris, J., and Lycett, J.: Mollusca Great Oolite, Pal.Soe., pt. 2, p. 26, PI. 6, 
9 (1853). 
* Prodrome, I, p. 255; Annales Pal. 3, p. 197 (61), PI. 20 (15), figs. 16, 17 (1908). 
