Messageria Bavay & Dautzenberg, 1904

Chen, Zhe-Yu & Lin, Li-Wen, 2021, Notes on the genus Messageria Bavay & Dautzenberg, 1904, with descriptions of a new speciesand anew subspecies (Gastropoda: Caenogastropoda: Cyclophoroidea Alycaeidae), Zootaxa 5067 (1), pp. 129-134 : 130

Messageria Bavay & Dautzenberg, 1904

Messageria Bavay & Dautzenberg, 1904: 230 .

Type species. Helicomorpha scalarioides Bavay & Dautzenberg, 1904 , by original designation.

Remarks. Messageria was introduced by Bavay & Dautzenberg (1904) with the obliquely positioned embryonic shell and stairs-like ribs ( Bavay & Dautzenberg, 1904; Thiele, 1929). Messageria was synonymized with Helicomorpha in previous studies ( Egorov, 2013; Bank, 2017). In comparison with Helicomorpha (SMF 105304, H = 1.5 mm, W = 1.5 mm), the shell of Messageria is significantly larger (see measurements below). More importantly, the outer surface of the operculum in Helicomorpha is flat or with an outward bulge / inward depression in the center (possibly caused by stripped multilayer structure), while in Messageria , the operculum is concave on the outside with multispiral lamina on the outer surface. Based on this diagnostic set we consider the two as separate genera. The columellar edge of the peristome in some Helicomorpha species is strongly expanded, such a trait that has not been found in Messageria . The obliquely positioned protoconch also appears in some species of Helicomorpha , however, such trait is not diagnostic as it is common in diplommatinids and alycaeids. Affiliates of Messageria see in Discussion.