Family Gastrocoptidae Pilsbry, 1918
One genus, Gastrocopta, occurs in Canada. Most species here have shells that are described in the old literature as the colour of “spermaceti”—a waxy substance in the head of whales and not likely having much meaning nowadays. But, Gastrocopta shells are often plastered with dirt and debris, rendering them rather more difficult to see.
This family, which is well represented in eastern North America, west into the South-eastern USA, but almost absent from north-western North America. In Alberta and BC, Gastrocopta are exceedingly rare. The family is also extant in Southeast Asia and Australia.
Canadian species Gastrocopta (Albinula) armifera (Say, 1821) Gastrocopta (Albinula) contracta (Say, 1822) Gastrocopta (Albinula) holzingeri Sterki, 1889 Gastrocopta (Albinula) similis (Sterki, 1909) Gastrocopta (Privatula) corticaria (Say, 1817) Gastrocopta (Vertigopsis) pentodon (Say, 1822) Gastrocopta (Vertigopsis) tappaniana (C.B. Adams, 1841)
Genus Gastrocopta Wollaston, 1878
- Gastrocopta Wollaston 1878: 515; type species by subsequent designation (Pilsbry 1916 [1916–1918]: 6): Pupa acarus Benson, 1856.
Etymology. Greek gaster, stomach or belly + kopto, to cut. Feminine.
Subgenus Albinula Sterki, 1893
- Albinula Sterki 1893: 101; type species by original designation: Pupa contracta Say, 1822.
Etymology. Latin: albus, white + diminutive suffix -ula.
Subgenus Privatula Sterki, 1893
- Privatula Sterki 1893: 101; type species by monotypy: Odostomia corticaria Say, 1817.
Etymology. Latin: privus, one or individual + diminutive suffix -ula.
Subgenus Vertigopsis Sterki, 1893
- Vertigopsis Sterki 1893: 101; type species by original designation: Pupa curvidens Gould, 1841 (= Vertigo pentodon Say, 1821).
Etymology. Vertigo + Greek, opsis, face or appearance, a reference to its rather Vertigo-like appearance.
Key to species of Gastrocopta in Canada
- 1a Palatal and basal folds absent and no palatal callus in adults – G. corticaria
- 1b Palatal and basal fold, as well as palatal callus present in adults – 2
- 2a Parietal fold simple, tubercle-like – 3
- 2b Parietal fold forked (joined to the angular fold as an angulo-parietal), sinuous and lobed – 4
- 3a Shell slenderer, more-or-less subcylindrical. Shell height in adults ≤1.8 mm – G. pentodon
- 3b Shell less slender, 1.3× …, ovate. Shell height in adults ≤2.2 mm – G. tappaniana
- 4a Angulo-parietal fold sinuous and lobed but not clearly forked – 5
- 4b Angulo-parietal fold clearly forked. Shell height in adults <2 mm – G. holzingeri
- 5a Aperture subtriangular. Spire distinctly conical, to tip – G. contracta
- 5b Aperture subovate. Spire barrel-shaped, with apex rather domed – G. armifera and G. similis