As espécies recentes reportadas para o gênero Meioceras Carpenter, 1858 (Mollusca: Caenogastropoda: Caecidae) no Atlântico oeste

Abstract

ln 1858 Carpenter stated the genus Meioceras and he also recognized more three genus as part of the family Caecidae Gray, 1850. However, now there is a controversy regarding the “status” of generic or subgeneric of the taxon in relation to Caecum Fleming, 1817. ln this study the taxon Meioceras is recognized as a valid genus apart from Caecum, based on conchililogical diagnostic characters: the helicoidal young shell and the swollen appearance in the first third part or in the middle of the shell. After the exam and comparison of 19 out of 20 type species described for the genus Meioceras to the Westem Atlantic: Caecum nitidum Stimpson, 1851; Meioceras nitidum Bean, M. S. (in Carpenter, 1858); M cornucopiae and M cornubovis, both Carpenter, 1858; M cubitatum, M deshayesi, M bitumidum, M. carpenteri, M coxi, M crossei, M moreleti, M subinflexum, M undulosum, M tumidissimum, M tenerum all Folin, 1869; M fischeri and M imiklis, both Folin, 1870; M leoni Bérillon (in Folin, 1874); M mariae Folin, 1881; M lermondi Dall, 1924; we concluded that they are all the sarne taxon, somehow poJjmorfic, according to their conchiliological characters and now they should be considered synonyms of Meioceras nitidum (Stimpson, 1851). Because the syntypes of the species were destroyed, the election of a neotype became necessary. For this, we will suggest the type species of the genusMeioceras cornucopiae Carpenter, 1858.