Ariolimax columbianus - The Pacific Banana slug’s camouflage
An illustration of various Pulmonata (and one predator arthropod in the lower right), an informal group of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. Pulmonata was previously a formal taxon but lost its status as one in 2010. The group includes many land and freshwater families, and several marine families. Most species have a shell, but no operculum, although the group does also include several shell-less slugs. Pulmonates are hermaphroditic, and some groups possess love darts.
(illustration by H. Morin, from The Royal Natural History, 1893)
From: ‘The collector’s manual of British land and freshwater shells’ Second Edition by L.E.Adams (1896)