|Five shells of Lucilla singleyana, scale bar is in mm|
The shell of this species is about 2 mm in width.
Pilsbry's original text (the type description) reads as follows:
|“||Zonites singleyanus Pilsbry. Proc. A. N. S. Philada., 1888, PI. xvii, figs. m,m,m.
Shell minute, broadly umbilicate, planorboid, the spire scarcely perceptibly exserted; subtranslucent, waxen white, shining, smooth, under a strong lens seen to be slightly wrinkled by growth-lines; whorls three, rather rapidly increasing, separated by well-impressed sutures, convex, the apex rather large; body-whorl depressed, slightly descending, indented below around the umbilicus; aperture small, semilunar, oblique; peristome simple, acute. Umbilicus nearly one-third the diameter of the shell, wide, showing all the whorls.
Alt. 1, diam. 2 mill.
Allied to Z. minusculus, but much more depressed, more shining, smoother, smaller, with broader umbilicus and a complete whorl less than minusculus.
This species, one of the most 'distinct of the smaller forms of Hyalina, was communicated to me by Mr. J. A. Singley, in whose honor it is named. I have also found a few specimens among the shells collected by myself in central Texas, during the winter of 1885-'86. With Z. singleyanus at New Braunfels are found quantities of Z. minusculus. The latter species exhibits some variation, being often more depressed than most northern specimen. This depressed form has been noticed in Mexico by Strebel,* who proposes for Z. minusculus the new generic title of Chanomphalus, which of course is completely synonymous with Pseudohyalina Morse, 1864, and this again is not different enough from Hyalina to warrant the erection of a new genus or sub-genus. There is some variation in the width of the umbilicus in Texan specimens of Z. minusculus, but I have not seen specimens with it so wide as Dr. Dall indicates for his var. alachuana, from Florida. H elegantulus Pfr. is about the size and form of my Zonites singleyanus, but it is a strongly sculptured species.
* Vide Beitrag zur Kenntniss der Fauna mexikanischer Land und Süsswasser Conchylien, Theil iv, p. 19, pi. iv, fig. 10. (1880.)
This species is Holarctic in distribution.
The indigenous distribution for this species includes North America.
Then non-indigenous distribution areas include:
This article incorporates public domain text from the reference.
- 2006 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Cited 28 May 2007.
- Pilsbry H. A. 14 May 1889. New and little known American mollusks, no. I. Proceedings of the Academy of Natural Sciences of Philadelphia 41: 81-89, pl. 3. Description is at page 84.
- (in Czech) Horsák M., Juřičková L., Beran L., Čejka T. & Dvořák L. (2010). "Komentovaný seznam měkkýšů zjištěných ve volné přírodě České a Slovenské republiky. [Annotated list of mollusc species recorded outdoors in the Czech and Slovak Republics]". Malacologica Bohemoslovaca, Suppl. 1: 1-37. PDF.
- Čejka, Tomáš (2000). "First record of the land snail Helicodiscus (Hebetodiscus) singleyanus inermis H. B. Baker, 1929 (Gastropoda, Punctidae) in Slovakia". Biologia, Bratislava. 55: 475–476.
- Horsák M., Šteffek J., Čejka T., Ložek V. & Juřičková L. (2009). "Occurrence of Lucilla scintilla (R.T. Lowe, 1852) and Lucilla singleyana (Pilsbry, 1890) in the Czech and Slovak Republics – with remarks how to distinguish these two non-native minute snails". Malacologica Bohemoslovaca 8: 24-27. Online serial at <http://mollusca.sav.sk> 18-June-2009.
- Balashov I. & Gural-Sverlova N. 2012. An annotated checklist of the terrestrial molluscs of Ukraine. Journal of Conchology. 41 (1): 91-109.
- Spencer H.G., Willan R.C., Marshall B.A. & Murray T.J. (2011). Checklist of the Recent Mollusca Recorded from the New Zealand Exclusive Economic Zone