Zonitoides (Zonitoides) arboreus (Say, 1817)
- Helix arboreus Say 1817a: unpaginated; pl. 4, fig. 4.
- Helix ottonis L. Pfeiffer 1840: 251.
- Helix breweri Newcomb 1864: 118.
- Hyalina arborea var. viridula Cockerell 1888: 257.
- Hyalinia (Polita) roseni Lindholm 1911: 98.
- Alienator lyndhurtoides Mclaughlan 1954: 40.
- Zonitoides (Zonitellus) azoricus Riedel 1964: 46, figs 38–40, 41, 42.
- ? Zonitoides ostauri Pilsbry 1926: 100, fig. 24.
Identification. Shell strongly depressed, subdiscoidal. Spire low, convex. Suture moderately impressed. Whorls c. 4½–5, convex. Protoconch smooth. Teleoconch with irregular, weak incremental wrinkles, weaker on base, and exceedingly faint spiral striae (difficult to see even under high magnification). Aperture deeply lunate, wider than high, edentulous. Lip thin, simple. Umbilicus c. 1/5 of shell width. Shell translucent, yellow- to red-brown, glossy or glassy. Shell width to 6 mm (wider than high).
This species lacks the dull orange spot on the mantle, which is evident in Z. nitidus, and the animal is paler. The shell has exceedingly fine spiral striae, which at c. 50× are still difficult to make out. Aegopinella nitidula is larger, the shell has relatively coarser spiral striae, and the umbilicus is larger and with a milky- white opacity surrounding it. Species of Oxychilus are smoother, glossier, and spiral striae are absent.
Habitat. A wide variety of natural habitats, including forests and open habitats, where it occurs under rocks, within rotten wood, leaf litter and vegetation.
Global range. Native to North America, south in Mexico to Veracruz and Puebla (Correa-Sandoval et al. 2007), Central America, and the West Indies. Introduced to South America, Europe, some North Atlantic islands, North and southern Africa, the Middle East, Japan, Australia (Long 1972, Bishop 1978, Smith 1992, Seddon 2008), and Hawaii (Pilsbry 1946, Barker 1999). Said to be native to Kamchatka (Dall 1905, Likharev & Rammel’meier 1962) and Japan (Likharev & Rammel’meier 1962).
Canadian range. Ubiquitous, in nearly every province and territory; likely in Nunavut (southern islands in Hudson Bay likely).
Etymology. Latin: of the trees.
Remarks. This species was described as Helix arboreus by Say (1817) in his article “Conchology” that appeared in volume 2 of the American Edition of the British Encyclopedia. Although usually dated 1816, this part was published in 1817 (Johnson 1975).
Syntypes of Helix whitneyi, which long considered a junior synonym of Z. arboreus (e.g. Pilsbry 1946), were examined by Roth (1988) who found them to belong to Discus (see Discus whitneyi).
- Barker GM (1999) Naturalised terrestrial Stylommatophora (Mollusca: Gastropoda). Fauna of New Zealand/Ko te Aitanga Pepeke o Aotearoa 38: 1–253.
- Bishop MJ (1978) Zonitoides arboreus (Say) (Pulmonata: Zonitidae) introduced into Australia and the identity of Alienator Iredale. Journal of the Malacological Society of Australia 4 (1-2): 7–8.
- Cockerell TDA (1888) Mollusca in Colorado. Hardwicke’s Science Gossip 24: 257.
- Correa-Sandoval A, Strenth NE, Salazar Rodríguez MC (2007) Zoogeografía de los gastrópodos terrestres del sur de Nuevo León, México. Acta Zoológica Mexicana (n.s.) 23: 143–162.
- Dall WH (1905) Land and fresh water mollusks. Harriman Alaska Expedition. Vol. 13. Doubleday, Page and Co., New York, 1–171, pls 1, 2.
- Johnson RI (1975) First paper on the conchology of the United States by an American author, Thomas Say, 1817. Journal of the Society for the Bibliography of Natural History 7 (3): 265–267.
- Likharev IM, Rammel’meier ES (1962) Terrestrial mollusks of the fauna of the U.S.S.R. Keys to the Fauna of the USSR. Israel Program for Scientific Translations, Jerusalem,  + 574 pp.
- Lindholm WA (1911) Bemerkungen über einige Hyalinien Russlands nebst Beschreibung einer neuen Art. Nachrichtsblatt der Deutschen Malakozoologischen Gesellschaft 43: 94–99.
- McLaughlan CF (1954) Land shells originally introduced. Australian Zoologist 12: 40.
- Newcomb W (1864) Descriptions of nine new species of Helix inhabiting California. Proceedings of the California Academy of Natural Sciences 3: 115–119.
- Pilsbry HA (1926) The land mollusks of the Republic of Panama and the Canal Zone. Proceedings of The Academy of Natural Sciences of Philadelphia 78: 57–126, pls 129–110.
- Pilsbry HA (1946) Land Mollusca of North America (north of Mexico), 2(1). The Academy of Natural Sciences of Philadelphia, Monographs 3: frontispiece, i–vi, 1–520.
- Pfeiffer L (1840) Uebersicht der im Januar, Februar und März 1839 auf Cuba gesammelten Mollusken. Archiv für Naturgeschichte 6: 250–261.
- Riedel A (1964) Zonitidae (Gastropoda) der Azoren. Boletim do Museu Municipal do Funchal 18: 5–60, 61 pls.
- Roth B (1988 “1987”) Identities of two Californian land mollusks described by Wesley Newcomb. Malacological Review 20: 129–130.
- Say T (1817a “1816”) Conchology. In: Nicholson W (Ed.) The First American Edition of the British Encyclopedia or Dictionary of Arts and Sciences, Comprising an Accurate and Popular View of the Present Improved State of Human Knowledge. First Edition. Vol. 2. Samuel A. Mitchell and Horace Ames, Philadelphia, 15 unnumbered pages, 4 pls.
- Seddon MB (2008) The landsnails of Madeira. An illustrated compendium of the land snails and slugs of the Madeiran archipelago. Studies in Biodiversity and Systematics of Terrestrial Organisms from the National Museum of Wales, Biotir Reports 2: viii + 204 pp.
- Smith BJ (1992) Non-marine Mollusca. Zoological Catalogue of Australia. AGPS, Canberra, xii + 405 pp. pp.