Strobilopsidae

Family Strobilopsidae Wenz, 1915

The Strobilopsidae is a small family of few genera distributed in temperate eastern and central North America south into the Neotropics. It is conspicuously absent from the north-western North America, although two other genera occur in East Asia (Pilsbry 1948, Schileyko 1998). There are roughly 10 species and subspecies of Strobilops in North America, mostly in the east, and south through the Caribbean and Central America to Venezuela and eastern Brazil. Three species occur in Canada, but none occur west of Manitoba.


Genus Strobilops Pilsbry, 1893

  • Strobila Morse 1864: 26; type species by monotypy: Helix labyrinthica Say, 1817; non Strobila M. M. Sars, 1835, nec Strobila Sodoffsky, 1837.
  • Strobilus Sandberger 1872 (1870–1875): 258; type species by original designation: Helix labyrinthica Say, 1817; non Strobilus Anton, 1839.
  • Strobilops Pilsbry 1893: 403; nomen novum pro Strobila Morse, 1864.

Etymology. Greek strobilos, a pinecone, + ops, having the appearance of; masculine.

Subgenus Strobilops Pilsbry, 1893

Strobilops (Strobilops) aeneus Pilsbry, 1926
Strobilops (Strobilops) affinis Pilsbry, 1893
Strobilops (Strobilops) labyrinthicus (Say, 1817)


Key to species of Strobilops in Canada

  • 1a Spire rather low conic; sides of spire only slightly con­vex. Base flattened and aperture not deeply rounded below; last whorl flattened. Last whorl compressed with periphery strongly angular. Basal folds 3 or 4; no palatal folds – S. aeneus
  • 1b Spire convex-conic or dome-shaped. Last whorl deep, not compressed; periphery rounded or bluntly angular. Base rounded and aper­ture deeply rounded; last whorl not flattened. Basal and palatal folds usually 5 or more – 2
  • 2a Basal folds very unequally sized. Mature shell width 2.3–2.5 mm – S. labyrinthicus
  • 2b Basal folds short and approximately equally long. Mature shell width 2.7–2.9 mm – S. affinis