86 
stream, and in the railway cut on the south slope of Grassy mountain. 
The Lille member lies 100 feet above the base of the formation and is 6 
feet thick. It is made up of coarse sand grains cemented by lime and 
contains many shells. A remarkable feature is the presence of numerous 
small, immature Ostrea and Gryphaea shells, about 10 mm. in diameter, 
and the absence of any adult Gryphaea shells. Most of the species of this 
fauna are at least of fair size and some have thick, coarsely ribbed shells. 
The fauna is fairly abundant in number of individuals, but contains only a 
few species and all are pelecypods. It includes the 8 species in the table 
listed under CF1, CGI, and CG15, i.e. Alectryonia informis, A. meevoyi, 
Chlamys mcconnelli , Camptonectes sp., Lima stantoni , L. whiteavsi, L. 
dowlingi, Plagiostoma blairmorensis 1 , and the immature shells of Gryphaea. 
Corbula munda Fauna 
The C . munda fauna is the most commonly occurring, the longest 
ranging, the most prolific in number of individual specimens, and the most 
diverse in species and genera. In the railway section along the southern 
base of Grassy mountain it overlies the Lille or C. mcconnelli fauna and 
ranges from 555 feet (CG3) to 800 feet (CG11) above the base of the 
formation. It also includes the shells collected on the creek north of 
Blairmore (CI1), in the drift between the two shale quarries (CJ2), and 
those in the Ferrier collection (CJ1). At all of these localities it is found 
in the hard, calcareous, fine-grained sandstone lenses. It is a fairly prolific 
fauna, chiefly of pelecypods, and contains 25 pelecypods, 5 ammonoids, a 
few small gasteropods, and worm tubes. The following species are of this 
fauna: Cucullaea living stonensis, Gervillia ferrieri, Inoceramus obliquiformis, 
Oxytoma blairmorensis, Pseudomonotis ferniensis , Ostrea dowlingi , Gryphaea 
impressimarginata, Trigonia ferrieri, Camptonectes cf. bellistriatus, Camp - 
tonectes sp. small specimens, Entolium leachi , Lima albertensis , Anomia 
albertensis, Modiolus rosii , M. frankensis , Pleuromya obtusiprorata, P. 
summissiornata, P. postculminata, Anatina cf. punctata , Thracia canadensis, 
Cyprina ? cf. iddingsi, Cyprina ? sp., Protocardia schucherti, Corbula munda , 
Astarte sp.,' Miccocephalites laminatus , M. miccus , M. concinnus, Meta - 
cephalites metastatus, Paracephalites glabrescens, P. jucundus , 2 Belemnites 
sp., and Serpula sp. Although all the ammonoids come from blocks thrown 
out in excavation, there is no doubt that they belong to this fauna; the 
pelecypods associated with them and the lithology of the matrix prove this. 
On Castle river, in the South Fork map-area, a restricted phase of this 
fauna is found in the two Gryphaea beds, of fine, slightly calcareous sand- 
stone, respectively at 270 and 325 feet below the Green bed horizon. In 
both beds G. impressimarginata is very abundant. In the upper bed a few 
specimens of Oxytoma blairmorensis, Lima stantoni ?, and Belemnites are 
also found. In the lower bed, in addition to the Gryphaea , are a few speci- 
mens of Oxytoma blairmorensis. Although of somewhat different facies 
this is the same fauna as that in the hard, calcareous, fine sandstone lenses 
of Blairmore area. 
1 For descriptions of these species See MoLearn, F. H.: Trans. Roy. Soo., Canada, 3rd sot., vol. 18, sec. IV, 
pp. 3M1, Pis. 1-9 (1924). 
* For descriptions of pelecypods See MoLearn, F. H.: Trans. Roy. See., Canada, 3rd eer., vol. 18, pp. 39-61, 
Pis. 1-9 (1924) and for descriptions of ammonoids See Buckman, S. S.: Jurassic Ammonoidea, this volume. 
