Webbhelix multilineata

Webbhelix multilineata (Say, 1821)
Striped Whitelip

  • Helix multilineata Say 1821: 150.
  • Helix multilineata var. rubra Witter 1878: 384.
  • Polygyra multilineata algonquinensis Nason 1906: 141.
  • ? Polygyra multilineata chadwicki Ferriss 1907: 37.
  • Polygyra multilineata var. altonensis F. C. Baker 1920: 65.
  • Polygyra multilineata var. wanlessi F. C. Baker 1928: 132.
  • There are a number of noma nuda, which were intended to denote various colour variants (see Binney 1858, Witter 1878, Walker 1906).
Webbhelix multilineata
Webbhelix multilineata.

Identification. Shell subglobose, with low, convex spire. Periphery rounded. Suture deep. Whorls 5–6, regularly increasing in size. Aperture broadly crescent-shaped, without denticles. Lip thin, reflected, not much expanded. Umbilicus closed by a callus but shallowly indented. Rather thin-shelled. Protoconch smooth. Teleoconch with narrow, closely spaced colabral riblets. Shell yellowish grey with reddish bands of various widths. Width to ca 20–25 mm (wider than high).

Webbhelix multilineata showing variation in size and banding; Pelee Island, Ontario (RGF 16.121.9340).

Within the Canadian populations there is considerable variation in the mature size of shells.

This is one of the few spirally banded polygyrids. The only other polygyrid with spiral bands in Canada is Allogona profunda.

Animal dark brownish grey, with tubercles paler; ocular tentacles darker.

Webbhelix multilineatus, Point Pelee, Ontario. 2016.

Habitat. Low, wet places in woods, marshes, wet meadows; living under driftwood and logs and in leaf litter. On Point Pelee and Pelee Island found lower, wetter areas in sandy Common Hackberry (Celtis occidentalis) woods and wet maple woods.

Global range. Ontario, Minnesota, Wisconsin, and Michigan, south to Arkansas and Mississippi, east to New York, Pennsylvania, and West Virginia, and west to Nebraska and Kansas (Pilsbry 1940, COSEWIC 2018).

Canadian range. Southwestern Ontario: Point Pelee, Pelee Island, and Walpole Island.

Although native to Canada, there was an attempt to introduce this species in Ottawa and Gatineau Park, Hull (now Gatineau), Quebec (Latchford 1887). The Ottawa colony rapidly disappeared, but in 1936, snails were still found in Quebec (Fairbairn 1937; FMNH 146361). Recent fieldwork (2016, R. Forsyth and A. Nicolai) in Gatineau Park and nearby sites failed to find this species there and the introduced populations is presumed to have perished (COSEWIC 2018).

Etymology. Latin: multi, many + lineata, lined.

Remarks. The inclusion of Polygyra multilineata chadwicki Ferriss, 1907 in the synonymy is unclear: Pilsbry (1940) treated chadwicki as a form or subspecies, but although Webb (1952) raised it to a full species, and Vagvolgyi (1968) and Hubricht (1985) believed it to be a synonym.

Grimm (1996) doubted that Webbhelix from Pelee Island are conspecific with W. multilineata and indicated that these are an undescribed new species. Some material in the CMNML collection was labelled by him with a manuscript name, but this taxon was never formally described.