Eighty-three fossil crabs, belonging to a new genus and species, and interpreted to be mainly exuviae, were collected from concretions within the Spray Formation at Shelter Point, Vancouver Island, British Columbia. They are assigned to the family Carcineretidae and named Longusorbis cuniculosus. The excellent preservation of the fossil crabs is a consequence of being buried in their own dwelling burrows in the intertidal zone, and subsequent formation of concretions around the specimens very early during diagenesis. Several species of mollusc occur with the crabs, and the faunal assemblage is assigned to the Pachydiscus suciaensis Zone of late Campanian to early Maestrichtian age. The small part of the Spray Formation exposed at Shelter Point contains six units of detrital sediment deposited in environments inferred to range from shallow neritic to supratidal.