64 
Conulana esclavensis n. sp. 
Plate XIII, figures 6a, b 
Shell small, apical angle about 24 degrees. Faces concave. Orna- 
mentation of faces of fine ridges which are uninterrupted over the marginal 
angles and are continuous across the faces. Ridges very slightly crenul- 
ated and on each face in the form of flattened chevrons with the apex 
away from the apex of the shell. 
The chevrons on the faces are not symmetrical, one side being more 
bent toward the apex of the shell than the other side. This is probably 
not a characteristic of the shell, but has resulted from the application 
of pressure along the marginal angle between the faces. 
Locality and Horizon . North arm, Great Slave lake, North West 
Territories. Ordovician. 
