Tandonia budapestensis (Hazay, 1881)
Description: Medium slug, extended length 5 - 6 cm. Colour varies from yellowish-grey through browns to dark grey, with a reticulation of black spots. Very slender when fully extended and it contracts into a characteristic C-shape, not a hump. Pneumostome rimmed with black. Keel clear yellow or orange. Sole yellowish-white, usually with a darker central stripe, but sometimes darker at the sides. Mucus colourless.
Habitat: Mostly in parks, gardens and crops, in association with man. A notable pest.
Tandonia sowerbyi (Férussac1823)
Description: Medium to large slug – extended length 6 – 7.5 cm. Body pale brownish-grey speckled with black, with grooves between tubercles also pigmented. Pneumostome with pale orange rim. Keel lighter than body, usually yellow or orange, crinkled when animal is contracted, not truncate. Sole whitish, mucus thick, yellowish and sticky. Some colour variants occur, and the keel is occasionally the same colour as the body.
Habitat: Gardens, hedges and agricultural land. Tends to be subterranean, and is a notable pest.
Boettgerilla pallens Simroth 1912
Description: small to medium slug, extended length 3 – 4 cm. Pale translucent greyish-yellow, with keel, back and head darker bluish-grey. Very narrow, almost worm-like, when fully extended. Sole pale yellow, mucus colourless.
Habitat: Mostly in gardens and parks, probably recently introduced in the west, more widespread and in woods in E. Europe.