29 
The septum, cardinal process, and triangular plates are all so thickened 
by deposits that it is difficult to decipher the exact course of the callosity 
from the edge of the septum which curves over to support the crural plates. 
Horizon and Locality. Richmond: Beaverfoot. Eleven hundred and 
fifty feet east of the trail on Palliser pass, Rocky mountains, British 
Columbia. 
PELECYPODA 
Byssonychia radiata var. walked n. var. 
Plate V, figures 19, 20 
Shell ventricose, medium size, outline ovate, disregarding the beak, 
anterior portion not alate, the tip of the beak and a part of the anterior 
margin not entire, umbones full, beak rather obtuse, prominent, and 
incurved, hinge-line short, flattened anterior ligamental area large, byssal 
opening not preserved, but judging from the curve of the concavity of the 
area it is placed high, posterior cardinal margin short, covered with thirty 
to forty striations, broader than the Intermediate grooves, rather coarser 
than is usual with B. radiata. 
This form is very similar to B. radiata in its general outline, in the 
shape and proportion of the ligamental area, and until better specimens 
can be procured it is considered as a variety of that species, though differing 
from it in having fuller beaks, in being more ventricose, especially in the 
umbonal region, in having a less extended posterior cardinal margin. In 
these features it approaches B. obesa, but the ligamental area occupies 
a larger proportion of the front of the shell than in that species. This 
large area is suggestive of B. alveolata, but the beaks are more incurved 
and the posterior cardinal portion is less pronounced. 
The variety is named after Mr. J. F. Walker, Geological Survey, 
Canada, who has procured the first pelecypod from these Rocky Mountain 
beds. 
Horizon and Locality. Richmond: Beaverfoot. At 95 feet above the 
base of the Beaverfoot from the head of Windermere creek, Rocky 
mountains, B.C. 
GASTROPODA 1 
Family, Euomphalidae de Koninck 
Genus, Palliserla Wilson 
This genus is like Madurina in its sinistral whorl, but is without an 
operculum so far as is known. It differs from Madurina essentially in its 
turbinate spire and in its ornamentation, in both of which respects it 
more closely resembles some members of the Trochoturbinidae {See 
Plate YI, figures 1, 2; Plate VII, figures 1, 2). 
i Descriptions abridged from original. Can. Nat., vol. XXXVIII, No. 8, p. 150. 
21215—3 
