Family Valloniidae Pilsbry, 1900

The Valloniidae is a small family of minute snails of the Northern Hemisphere, with species introduced elsewhere. There are three genera—Zoogenetes, Vallonia, and Planogyra—in Canada. Subfamilies are sometimes used in classifications of this group: Valloniinae and Acanthinulinae. Following this system, Zoogenetes would be placed within Acanthinulinae, an assortment of oddball genera, and Planogyra in either Acanthinulinae or Valloniidae. However, these subfamilies are artificial (e.g., Giusti & Manganelli 1986) and are not often used nowadays (e.g., Bouchet et al. 2017). Indeed, genetic data have suggested that the Valloniidae is paraphyletic and that the Acanthinulinae does not constitute a part of the family (Armbruster et al. 2005), the acanthinuline genera are retained here for now.

Species in Canada
Planogyra asteriscus (Morse, 1857)
Planogyra clappi (Pilsbry, 1898)
Vallonia costata (O. F. Müller, 1774)
Vallonia cyclophorella Sterki, 1892
Vallonia excentrica Sterki in Pilsbry, 1893
Vallonia gracilicosta Reinhardt, 1883
Vallonia parvula Sterki in Pilsbry, 1893
Vallonia pulchella (O. F. Müller, 1774)
Vallonia terraenovae Gerber, 1996
Zoogenetes harpa (Say, 1824)

Genus Planogyra Morse, 1864

  • Planogyra Morse 1864: 24; type species by monotypy: Helix asteriscus Morse, 1857.

There are two species in North America (Pilsbry 1948), and one species, Planogyra borealis (Pilsbry & Hirase, 1905), in Japan and the Russian Far East, including Kurile, Moneron, and Sakhalin islands (Sysoev & Schileyko 2009).

Etymology. Latin: planus, flat + Greek: gyros, whorl. Masculine.

Key to Species of Planogyra in Canada

  • a Umbilicus ca ¼ of shell width. Colabral riblets ca 35 on last whorl. British Columbia — P. clappi
  • b Umbilicus ca ⅓ of shell width. Colabral riblets ca 18–30 on last whorl. Eastern and Atlantic Canada — P. asteriscus

Genus Vallonia Risso, 1826

  • Vallonia Risso 1826: 101, type species by monotypy: Vallonia rosalia Risso, 1826 (= V. pulchella O. F. Müller, 1774).

With about 40 species and subspecies in North America, Eurasia, and North Africa, Vallonia has the greatest number of species and broadest distribution of any valloniid genus. Eight species of Vallonia occur in Canada.

Etymology. Named after either for the Roman goddess of valleys, Vallonia (Pilsbry 1948), or perhaps after the town of Vallon, Ardèche, south-central France (Kennard & Woodward 1926). Feminine.

Genus Zoogenetes Morse, 1864

  • Zoogenetes Morse 1864: 32; type species by monotypy: Helix harpa Say, 1824.

There is a single alpine-boreal Holarctic species.

Etymology. Greek: zoion, animal + genesis, birth (Pilsbry 1948); masculine.