Remarks on the suborder Involutinina Hohenegger and Piller, 1977

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Abstract
The test wall of Planispirillina papillosa (Cushman) is composed of aragonite, as shown by X-ray determination. The test is built of a semitube, which surrounds the deuteroloculus and which is followed by a lamella with papillae, covering 1 side of the test. These characteristics necessitate a classification of Planispirillina with the Involutinidae. Besides the description of 2 spp. of the genus Planispirillina (P. papillosa, P. denticulata), the new genus TROCHOLINOPSIS (type species T. porosuturalis sp. nov.) is described from Recent sediments of the Strait of Sicily. Trocholinopsis also belongs to the Involutinidae. The generic concept of the Involutinidae, especially the Triassic representatives, is discussed, as is the phylogenetic relationship between the Involutinidae and the Archaediscidae. Both families are placed together in the Involutinina. For trochospiral forms with a canal system in the umbilical area the new genus HOTTINGERELLA, type species H. chouberti (Hottinger) comb. nov. (Trocholina chouberti), is established and the homonym Mesodiscus Piller, 1978, is renamed Triadodiscus nom. nov. Several genera previously placed among the Involutinidae are also discussed. Genera included in the Involutinidae are listed [in addition to those mentioned: Involutina, Auloconus, Aulotortus, Coronipora, Lamelliconus, Semiinvoluta, Triasina].