Remarks on the Genus Nerinæa , with an Account of the Species found in Portugal

T he genus Nériné was proposed by M. Defrance, in the ‘Dictionnaire des Sciences Naturelles,’ for certain species of turreted univalves found among the oolites, distinguished by having both the columella and the interior of the outer lip furnished with folds which are continued through the whole of the whorls; hut as M. Defrance had not then seen any perfect specimens, he did not give any strict definition of his new genus. M. Deshayes gave definite characters to the genus under the name of Nerinæa , in the ‘Coquilles caractéristiques des Terrains,’ p. 203, the principal points of which are the mouth subquadrangular ? canaliculated; a broad umbilicated columella with strong spiral folds; and one or more folds on the interior of the outer lip. Thus far the genus presents well-defined limits; and if we omit the perforation of the columella from its distinctive characters, it consists of a natural group of species. But succeeding authors have broken through all the boundaries of the genus laid down by M. Deshayes, and admitted many species which do not come under his definition of Nerinæa . Voltz, who has added largely to our knowledge of the species, includes in Nerinæa shells with a rhomboidal mouth and at least one internal fold (Jahrbuch, 1836, p. 538), thus admitting N. grandis and N. depressa , which have only a fold on the columella, and have the outer lip simple: in this he is followed by Bronn, and practically also by Goldfuss, who, while defining the genus as having