[2] The holotype specimen was collected on Sucia Island from the south side of Fossil Bay in a group of rock described as "Haslam fossiliferous shale".

The area was stated by Roy Davidson McLellan to be fossil rich and Ward in 1978 assigned the strata to the Campanian age Cedar District Formation.

[3] The formation has also preserved fossils of other terrestrial organisms including a basal cornalean flowering plant, Suciacarpa starrii and a theropod femur, the first dinosaur identified from Washington State.

[4] C. suciensis was first described by McLellan in his 1927 Geology of the San Juan Islands based on the single fossil recovered during field work for his thesis.

[1] The holotype fossil was reexamined in 1999 by Barry Roth of the University of California, who noted the shell thickness and uniform nature is similar to many non-marine pulmonate gastropods.