NOTES ON THE ALBERS, 1850 (, , )1

by ABRAHAM S. H. BREURE (Department of Systematicsand EvolutionaryBiology, Rijksmuseum van Natuurlijke Historie, Leiden, The Netherlands) and GUY COPPOIS (Laboratoirede ZoologieSystématique, Université Libre de Bruxelles,Belgium)

SUMMARY

The genus Naesiotus Albers, 1850, which previously also has been considered a subgenus or a synonym of Leach, 1814, has provisionally been studied at the species level. The variation of the shell morphology of 60 species and the analysis of the anatomical data of 23 taxa do not justify a division of Naesiotus in different subgenera. Bulimulusgilderoyi Van Mol, 1972 is placed in the synonymy of Naesiotus cavagnaroi A. G. Smith, 1972. Lectotypes are designated for 10 taxa and new localities are mentioned for 5 species. INTRODUCTION

The genus Naesiotus was introduced by ALBERS in 1850 and included six species, viz. calvus (Sowerby), eschariferus (Sowerby) jacobi (Sowerby), nux (Broderip), rugiferus (Sowerby) and ustulatus (Broderip). ALBERS (1960) selected nux (Broderip) as the type species of Naesiotus and listed seven additional species. PILSBRY (1897) followed all previous authors and restricted Naesio- tus to the species described from the Galapagos. He introduced the name Protoglyptus for the species with the same type of protoconch sculpture from the West Indies and eastern South America. DALL (1893, 1895, 1896, 1900, 1917, 1920) and DALL & OCHSNER (1928) extensively reviewed the land shell fauna of the Galapagos and created many new species and "sections" in Bulimulus (Naesiotus). Subsequent additions to our knowledge of the Galapagos bulimulids were made by PILSBRY (1946), ODHNER (1951), A. G. SMITH (1971, 1972, 1974), VAN MOL (1972) and VAGVOLGYI (1977). Meanwhile, REHDER (1940) was the first to realize that Naesiotus species were also found on the continent, e.g., Naesiotus quitensis 1 Contribution no. 241 from the Charles Darwin Foundation for the Galapages Islands. 162

(Pfeiffer) from Ecuador. Subsequently WEYRAUCH (1956) synonymized Protoglyptus Pilsbry, 1897, with Naesiotus Albers, 1850, and described several new species from Peru. Other authors, however, still consider Protog#pus as a separate genus (PARODIZ, 1962, 1979 [cf. Table Ij ; REZENDE & LANZIERI, 1963; LANZIERI & REZENDE, 1971; REZENDE, LANZIERI & INADA, 1972). ZILCH (1960) has treated Naesiotus as a subgenus of Bulimulus Leach, 1814, while VAN MOL (1972) considers Naesiotus a synonym of Bulimulus. In the present paper Naesiotus is tentatively treated as a separate genus and Protog1;yptus is considered a synonym. Naesiotus differs mainly from Bulimulus by ( 1 ) the different internal structure of the phallus complex: epiphallus not penetrating in distal part of penis; (2) the different structure of the protoconch. The analysis of Naesiotus as presented in this paper is only a tentative one, as not all taxa could be studied.

MATERIAL AND METHODS

The alcohol material used in the present studies was collected by the authors and J. J. VAN MOL (IRSN, RMNH), R. BLOMBERG (NRS), J. L. DE BARROS ARAUJO & H. E. B. REZENDE (MN, RMNH), W. WEYRAUCH (IML, SMF) and F. G. THOMPSON (UF). Histological studies were performed by the first author. After em- bedding in paraffin the material was sectioned at 7 and stained with Alcian Blue after kaliumpermanganate oxidation, followed by Haemalum and Phloxine. Some slides were stained with Haemalum and Eosin-Erythrosin. The histological slides have been deposited in the Leiden museum. Scanning electron micrographs were made following the procedure Of PLOEGER & BREURE (1977). Material was examined from the following museum collections: British Museum (Natural History), London (BMNH); Instituto Miguel Lillo, TucumAn (IML); Institut Royal des Sciences Naturelles, Brussels (IRSN); Museo Argentino de Ciencias Naturales, Buenos Aires (MACN); Museu Nacional, Rio de Janeiro (MN); Naturhisto- riska Riksmuseet, Stockholm (NRS); Rijksmuseum van Natuurlijke Historie, Leiden (RMNH); Natur-Museum Senckenberg, Frankfurt am Main (SMF) and Florida State Museum, Gainesville (UF). The following abbreviations are used in the drawings of the anatomy: AG, albumen gland; EP, epiphallus; FL, flagellum; N, nerve; P, penis; PD, distal part of penis; PP, proximal part of penis; PR, prostate; PS, penis sheath; RM, retractor muscle; SD, spermathecal duct; SP, spermatheca; V, vagina; VD, vas deferens.