11 
Horizon and Locality of Type. Foremost beds of the Belly River 
formation; northwest of centre of sec. 1, tp. 3, range 12, W. 4th mer., 
southern Alberta. 
Campeloma praecursa sp. nov. 
Plate III, figure 6 
Shell of moderate size, conical in outline; the volutions, which number 
five or six in those specimens having the apex preserved, flat-sided; body 
whorl slightly angulated at the base; surface marked by fine lines of growth, 
which in a few specimens are crossed by obscure revolving strise, suture 
very slightly impressed; aperture narrow, ovate; apparently imperforate. 
This species is distinguished from C. veiula tenuis by the flatness 
of the whorls, and, in consequence, the conical outline of the shell. It is 
quite similar to C. producta, but differs in the flatness of the whorls, there 
being no hint of a revolving ridge as in that species. C. praecursa is the 
forerunner of C. producta and allied species so common in the post-Bearpaw 
formations, just as C. vetula is the forerunner of C. multilineata. 
It has been found in both the Pale beds and Foremost members of 
the Belly River formation, but is more abundant in the lower member. 
Dimensions of Type. Length (one whorl missing), 18 mm.; breadth, 
10 mm. ; apical angle, 35 degrees. 
Campeloma cypressensis sp. nov. 
Plate III, figure 7 
This species has developed directly from C. producta^ there being 
many specimens intermediate in form between the two. C. cypressensis 
is distinguished by the very prominent shoulder in the upper part of the 
body whorl; this shoulder is so prominent in some specimens as to form 
a swollen ring which is much the widest part of the shell. The body whorl 
is much more robust porportionately than in C. producta, as a consequence 
of which the apical angle becomes considerably larger. The most extreme 
specimen measured 18 mm. in length and had an apical angle of 70 degrees. 
It occurs only in the Ravenscrag formation in Cypress hills in sec. 29, 
tp. 8, range 4, W. 4th mer. 
Dimensions of Type. Length, 14 mm.; breadth, 11 mm.; apical angle, 
70 degrees. 
Goniohasis svhtortuosa mut. tenuis n, mut. 
Plate III, figures 9, 10 
The remains of a gasteropod species closely resembling G. suhtortuosa 
of the Foremost beds was found in the Willow Creek formation in the bed 
of Willow creek a few miles west of the village of Granum (sec. 12, tp. 16, 
range 27, W. 4th mer.). The Willow Creek form, however, differs in 
being somewhat thicker shelled, more slender, and in having coarser growth 
lines. Owing to these differences and to its much higher geological horizon, 
it is herein regarded as a mutation of G. suhtortuosa. 
Dimensions of Type. Length, 12 mm.; breadth, 7 mm.; apical angle, 
40 degrees. 
