Belongs within: Limacoidei.
Glyphyalinia snails
Published 29 May 2022
North America (as with pretty much everywhere in the world outside the coldest regions) is home to a wide diversity of small, terrestrial snails that tend to pass unnoticed. Among the more diverse of these is the zonitid genus Glyphyalinia.
Glyphyalinia species are often found in forest leaf-litter in the eastern part of North America. They have a low, translucent shell that is often about half a centimetre in diameter. Whorls of the shell increase regularly in size and are marked by a series of strongly impressed radiating lines in addition to finer growth lines. The umbilicus of the shell varies between species from completely absent to quite wide (Burch & Pearce 1990). The soft body of the animal varies in coloration, again depending on species. That of G. roemeri is all white except for the eyes; that of G. wheatleyi is almost uniformly black. The reproductive system of Glyphyalinia (which are hermaphroditic) includes a well-developed epiphallus and a distinct, ovoid spermathecal sac (Baker 1930).
Multiple species of Glyphyalinia may be found living in a single patch of forest though, at present, we know little about how (and whether) micro-habitats are partitioned between species. Some species seem to tolerate a wide variety of soil types and are correspondingly widely distributed. Others are more selective and localised; some may be considered endangered by habitat degradation. Even supposedly widespread species may be more vulnerable than appreciated: at least some may represent clusters of closely related species rather than truly uniform populations. These tiny snails can be notoriously difficult to study, making for a risk that they might just slip away barely noticed.
Systematics of Glyphyalinia
<==Glyphyalinia Martens 1892BP90
|--G. clingmaniBP90
|--G. cryptomphalaH65b
|--G. cumberlandianaH65b
|--G. floridanaH63
|--G. indentataBP90
| |--G. i. indentataBP90
| `--G. i. paucilirataBP90 [=Retinella (Glyphyalinia) indentata paucilirataH65b]
|--G. lewisianaH68
|--G. luticola Hubricht 1966H66
|--G. pecki Hubricht 1966H66
|--G. praecoxH68
|--G. raderiBP90
|--G. rhoadsiBP90
|--G. roanensis (Baker 1930) [=Retinella (Glyphyalis) cumberlandiana roanensis]H65b
|--G. sculptilis [incl. Retinella (Glyphyalinia) sculptilis subdola Baker 1930]H65b
|--G. solida (Baker 1930) [=Retinella (Glyphyalinia) cryptomphala solida]H65b
|--G. specus Hubricht 1965H65a
|--G. virginicaBP90
`--G. wheatleyiH68
*Type species of generic name indicated
References
Baker, H. B. 1930. The North American Retinellae. Proceedings of the Academy of Natural Sciences of Philadelphia 82: 193–219.
[BP90] Burch, J. B., & T. A. Pearce. 1990. Terrestrial Gastropoda. In: Dindal, D. L. (ed.) Soil Biology Guide pp. 201–309. John Wiley & Sones: New York.
[H63] Hubricht, L. 1963. Some Succineidae, with a new species. Nautilus 76 (4): 135–138.
[H65a] Hubricht, L. 1965a. Four new land snails from the southeastern United States. Nautilus 79 (1): 4–7.
[H65b] Hubricht, L. 1965b. Notes on Zonitidae. Nautilus 78 (4): 133–135.
[H66] Hubricht, L. 1966. Four new land snails. Nautilus 80 (2): 53–56.
[H68] Hubricht, L. 1968. The land snails of Mammoth Cave National Park, Kentucky. Nautilus 82 (1): 24–28.