2 
Beaks prominent, incurved, directed anteriorly, and overhanging the 
anterior dorsal margin. Basal margin gently arcuate, posterior dorsal 
margin strongly curved to the short hinge-line. 
Shell thin, smooth closed, marked by varying lines of growth; lunule 
absent, escutcheon short and narrow. 
Pallial line entire, muscular scars as in Arctica but not well defined in 
the specimens studied. 
Teeth, as seen in sectioned specimens, consist of 3 cardinals and one 
lateral in each valve, generally similar to those of the V. conradi (Morton), 
This form corresponds in general characters with “C^/prmo" suh- 
trapeziformis Whiteaves^ Whiteaves did not see the hinge of his species 
and placed it doubtfully in “Cyprina” stating that it might belong instead 
to Cypricardia or Veniella. 
y. suhtrapeziformis var. dyeri differs from Whiteaves' form in being 
smaller, more gibbous, having more overarching beaks and a more arcuate 
basal margin. The following measurements illustrate the differences. 
V 
Measurements in mm. 
Whiteaves’ 
species 
Typical specimens of 
new variety 
1 
2 
3 
4 
5 
Height 
15 
12 
14 
13 
13 
14 
Rroadth at iimho 
10 
11 
12 
11 
11'7 
12 
18 
Length 
23-5 
16 
17 
16 
17 
Variety dyeri appears to belong to Stoliczka's genus Veniella, but 
differs from the general form in lacking a lunule. Its subquadrate or 
sub-trigonal shape separates it from Arctica. Within the genus Veniella, 
it is somewhat similar to V. suhtumida Meek and Hayden, from the Fox 
Hills and Fort Pierre groups of Yellowstone river, but differs from that 
species in somewhat smaller size and less rounded and prominent posterior 
umbonal shape. The depression in front of the slope in suhtumida is 
entirely lacking in internal casts of the present species, which have been 
used in comparison with the figures of internal casts of suhtumida in United 
States Geol. Survey of the Territories, vol. IX, PI. 17, figs. 5a, b. 
Occurrence. In the Baculites compressus zone 450 feet above the 
base of the Bearpaw formation, as exposed on Gap creek, sec. 24, tp. 9, 
range 27, W. 3rd mer. Collector, W. S. Dyer. Two lots of fossils, one 
marked SW. \ sec. 24; the other marked sec. 24, presumably came from 
nearly the same place. Together they contain upwards of eighty separate 
specimens, in fair state of preservation, and several pieces of rock packed 
full of specimens. Strangely enough the form has not been noted else- 
where in the region. 
With this species are found Chlamys nehrascensis M. and H., BacuUtes 
compressus Say, and Dentalium gradle H. and M. 
>Geol. Surv,, Canada, Cont. to Can. Pal., vol. I, p. 29, FI. XXIV, figs. 2, 2a, 2b. 
