Whitella canadensis
(from P.E. Raymond's "Fauna of the Chazy Limestone". American Journal of Science, Fourth Series, Vol. XX:373, 1905)
Whitella canadensis sp. nov.

Shell small, convex, subrectangular in outline.  A prominent ridge extends from the beak to the lower posterior corner.  From this ridge the slope to the cardinal and posterior margins is abrupt, while there is little slope to the front until a point in front of the beak is reached, when the slope is suddenly deflected.  The surface is marked by concentric undulations.

Locality.--Aylmer sandstone, Aylmer, Quebec.