Neohelix - Whitelip Snails (Family Polygyridae)
Three species of Neohelix, the Whitelip Snails, have records in Indiana. Neohelix albolabris is the most common. It is a large woodland snail lacking teeth with a closed umbilicus and a subglobose shell.
Neither of the other two species are listed for Indiana in Nature Serve, but do have museum records. Neohelix alleni is the Western Whitelip, once a subspecies of N. albolabris. Baker (1939) noted both in Illinois, as does Nature Serve. N. dentifera is found in extreme southeast Kentucky and Ohio, but not Illinois. The single specimen of N. dentifera has a modern re-identification, so is considered as possible.
Neohelix albolabris joins a "select" group of larger globose snails lacking teeth that includes species list in the F2 section of Group F.: Neohelix alleni (Western Whitelip Snail), Mesodon mitchellianus (Sealed Globelet Snail), Mesodon normalis (Grand Globe Snail), and Patera pennsylvanica (Proud Globelet Snail).
Neohelix albolabris (Say, 1817)
Neohelix albolabris (Say, 1817)
Common Name: (Eastern) Whitelip Snail
Characters: Heliciform, reflected lip, subglobose, imperforate; size ~ 17-45 mm diameter; one of the largest eastern snails.
Comparison: This species might be confused with Mesodon zaletus, another large Polygyrid snail, but it has a tooth (which may be lost in some shells). This species is distinguished from the Big-tooth White Lip which has, as you might imagine, a large parietal tooth and is thinner.
Habitat: mixed hardwood forests, base of limestone cliffs (Dourson 2015); in leaf litter or among rocks or logs in forests; preference for damp habitats, often on lower forest slopes with coarse woody debris (Hubricht 1985)
Status: distributed widely in the state in suitable habitat.
see image of Neohelix dentifera
Neohelix dentifera (A. Binney, 1837)
Common name: Big-tooth Whitelip Snail
Characters: Heliciform, reflected lip, subglobose to slightly depressed, imperforate; size ~ 11-17 mm diameter.
Comparison: Based on the range maps on Nature Serve, this species is out of its range here, but it has been collected in Ohio and Kentucky. This species might be confused with Mesodon zaletus, that also has a large parietal tooth. M. zaletus is more globose and, according to Dourson (2015), has a smaller parietal tooth. This species is distinguished from the other White Lips by the parietal tooth.
Habitat: in and around leaf litter in hardwood forests, may be associated with rocks and logs on acidic soils (Dourson 2015)
Status: There two findngs of this species (Marion and Henry counties), so the status is not known.
Neohelix alleni (Sampson, 1883)
Neohelix alleni (Sampson, 1883)
Common name: Western Whitelip
Characters: Heliciform, reflected lip, subglobose to slightly depressed, imperforate; size ~ 22-28 mm diameter.
Comparison: Based on the range maps on Nature Serve, this species is out of its range here, but it has been collected in Illinois.
From Oesch et al. (2013):
"Neohelix alleni [Western Whitelip] was originally described as a variety of N. albolabris [Eastern Whitelip], and later elevated to species rank by Hubricht (1965a). These species are very similar, and are distinguished by the basal lip, which in N. alleni usually forms a distinct node (or thickening), and in N. albolabris, the basal node is absent or inconspicuous (Emberton 1988). Neohelix albolabris also occurs primarily east of the Mississippi River, with a western subspecies (N. albolabris bogani Emberton) found from Arkansas south to Mississippi, Louisiana and Texas (Emberton 1988)."
​Baker (1939) compared the peristome of the two (subspecies at that time) this way: N. albolabris albolabris with "peristome wide and pure white" and N. albolabris alleni with "peristome narrow and pinkish in color"
Habitat: primarily woody debris (branches and bark). Hubricht (1985) describes the habitat as: "... wooded hillsides and in ravines, under logs and rocks, in leaf litter, and along roadsides and railroads; and on waste ground in urban areas."
Status: There has been only one record of this species (Jefferson County), so the status is not known.
revised: 1/23