Vitrina angelicae

Vitrina angelicae Beck, 1837
Eastern Glass-snail

  • Vitrina angelicae Beck 1837 (1837–1838): 1.
  • Vitrina limpida Gould 1850: 243.
  • Vitrina americana L. Pfeiffer 1854: 156.

Identification. Shell depressed-subglobose, very thin, delicate. Whorls 2½–3, rapidly enlarging. Spire small, low, domed. Suture well indented, with “false suture” evident. Protoconch smoothish, with scattered, microscopic punctae. Teleoconch with irregular, microscopic striae which are more wrinkle-like near suture. Aperture capacious, subovate, edentulous, wider than high; viewed from side, strongly prosocline. Lip thin and delicate, simple. Shell translucent yellow-green to nearly transparent and colourless (opaque and whitish when weathered).

Anatomically distinguished from Vitrina pellucida in having penis not enclosed by a sheath (sheath altogether absent) and duct of bursa copulatrix narrowed at its base (not swollen).

Shells of V. angelicae and V. pellucida are probably indistinguishable, although Pilsbry (1946) remarked that shells of the former are a little flatter and with the microscopic punctae less extensive, smaller, and irregularly scattered (not in spiral rows).

Habitat. Gravelly and grassy roadsides, in meadows, and in open woods. Under rocks and dead wood but often crawling in the open during cool, wet weather.

Global range. Eastern North America from Labrador to Pennsylvania and Michigan; southwest coast of Greenland (Pilsbry 1946, Forcart 1955, Hubricht 1985). In the USA, as in Canada the east–west limits of the two Vitrina species are uncertain.

Canadian range. Uncertain, but presumably all or most of Ontario east through Quebec to the Maritime Provinces, Newfoundland, and Labrador. The identity of Vitrina in Manitoba and Saskatchewan needs study.

In the older literature, V. limpida (now V. angelicae; see Remarks) has been reported from Alberta; however, all material examined from that province is V. pellucida.

Etymology. Named for the plant, Garden Angelica (Angelica archangelica), among which Danish naturalist Otto Fabricius (1744–1822) found these snails (Pilsbry 1946).

Remarks. This species is best known as V. limpida in North America (e.g., Pilsbry 1946, Hubricht 1985). Forcart (1955) recognized two subspecies, V. angelicae angelicae from Greenland and V. angelicae limpida from North America. However, he found no differences in the genital anatomy of these taxa and remarked that shells with the same number of whorls were larger in angelicae than in limpida (Forcart 1955), but this purported difference seems trivial and may be due to environmental conditions. The original and sole locality of V. limpida mentioned by Gould (1850) is at Cape Gourganne, Nipigon Bay, Ontario. Vitrina pellucida may extend east as far as Manitoba, which suggests that northern Ontario specimens of Vitrina should be anatomically or molecularly studied to confirm that V. angelicae and V. limpida are the same species. The western limits of V. angelicae and eastern limits of V. pellucida have not been worked out in Canada or the USA. Identifications of Vitrina should be confirmed by the study of genital anatomy.