MolluscaBase taxon details
original description
(of Helix fuliginea L. Pfeiffer, 1841) Pfeiffer, L. (1841). <i>Symbolae ad historiam Heliceorum</i>. Sectio prima [vol. 1]. Kassel: Th. Fischer. 88 pp. , available online at https://biodiversitylibrary.org/page/12254132
page(s): 37 [details]
original description
(of Helix nigrescens W. Wood, 1828) Wood, W. (1828). <i>Supplement to the Index Testaceologicus; or A catalogue of shells, British and foreign</i>. Richard Taylor, London. iv [+1] + 59 pp., plates 1-8. , available online at http://biodiversitylibrary.org/page/22991199
page(s): 22, pl. 7, Helix fig. 32 [details]
From editor or global species database