A Guide for Terrestrial Gastropod Identification - University of ...

Helicodiscus nummus (Vanatta, 1899) G1G2 AR, KY, OK, TX
AL, AR, CT, DE, FL, GA, IA, IL, IN, KS, KY, LA, MA,
MD, ME, MI, MN, MO, MS, NC, NE, NH, NJ, NY, OH,
OK, PA, RI, SC, TN, TX, VA, VT, WI, WV; Canada: NB,
Helicodiscus parallelus (Say, 1817) G5
NS, ON, QC, NF
Helicodiscus punctatellus Morrison, 1942 G1 KY, TN
Helicodiscus salmonaceus Hemphill, 1890 G2 ID, WA
Helicodiscus saludensis (Morrison, 1937) G1 NC, SC
CT, IA, IL, IN, KY, MA, MD, ME, MI, MN, NH, NY, PA,
Helicodiscus shimeki Hubricht, 1962 G4G5
TX, VA, VT, WI, WV; Canada: ON
AL, AR, CA, DE, IL, IN, KS, KY, LA, MD, MI, MO, NE,
NJ, NM, NY, OH, OK, PA, TN, TX, VA, WI, WY; Canada:
Helicodiscus singleyanus (Pilsbry, 1889) G5
ON
Helicodiscus tridens (Morrison, 1935) G2 OK, TX
Helicodiscus triodus Hubricht, 1958 G2 NC, VA, WV
Polygyriscus virginianus (P.R. Burch, 1947) G1 LE VA
Helminthoglyptidae
Mark A. Ports, Great Basin College
The family Helminthoglyptidae is a diverse and widespread group of land snails from
California, Oregon, Arizona, New Mexico, and west Texas. This family is composed of eleven
genera with approximately 83 species of Helminthoglypta, 13 species of Sonorelix, 9 species of
Micrarionta, 1 species of Chamaeariontales, 1 species of Herpeterous, 8 species of Xerarionta,
2 species of Cahuillus, 7 species of Eremarionta, 1 species of Noyo, 4 species of Rothelix, and
72 species of Sonorella.
The Helminthoglyptidae vary in diameter from 5 mm to 4 cm, and range from a dark
brown color to a pearly white color. The shells are generally depressed-helicoid in shape, thin in
texture, with a thin, reflexed peristome, normally without aperatural teeth. Most have a single
dark supra-peripheral band while some of the Mohave Desert species may not have any band. In
all of these genera (especially the Sonorella) the best way to identify them is the dissection of
their genitalia or the study of their phylogeny.
This family occupies habitat types that include wet temperate forest in Oregon and
northern California, dry coniferous and deciduous forests of the west side of the Sierra Nevada,
coastal mountains and canyons of conifers and oak, chaparral brush of coastal California, desert
valleys and mountains of California, Arizona, Texas and New Mexico. Most species of this
family are associated with rocky or talus slopes and ledges of dolomite, granite, or shale.
Existing in large to small colonies most species are active in the morning and evening or after
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