New species of Thaumastus from Lagoa Santa region , Minas Gerais State , Brazil ( Mollusca , Gastropoda , Pulmonata , Bulimuloidea ) 1

A new species of Thaumastus (Thaumastus) Martens, 1860, from Minas Gerais State, Brazil, is described and illustrated, based on the morphology of the shell, jaw, radula and soft parts.

Thaumastus Martens, 1860 was described as a subgenus of Bulimulus Leach, 1814, with Bulimus hartwegi Pfeiffer, 1846 as the type species.STREBEL (1910) described the six subgenera in Thaumastus based on sculpture of the protoconch while ZILCH (1960) and BREURE (1979) provided data on shell and soft parts.At present, fifty seven species are recognized.The shell of the species in this genus is relatively large, oval-elongated, brownish, mostly with axial streaks and spiral light bands, suture impressed and aperture oval or ear-shaped with thick peristome.In addition, the presence of a columellar callus, expanded or not, with rectilinear or rounded contour is an additional character which helps identify these species.

MATERIAL AND METHODS
The material studied consists of shells and specimens deposited in the Mollusks Collections of Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro (MNRJ), Museu de Zoologia de São Paulo, Universidade de São Paulo (MZSP), Brazil and Zoologisches Museum der Universität Hamburg (ZMH), Germany.
The identification was done by comparison with type material and adult shells deposited in MNRJ and MZSP, Brazil; The Academy of Natural Sciences of Philadelphia (ANSP), Philadelphia, USA; Forschungsinstitut und Naturmuseum Senckenberg (SMF), Frankfurt and Museum für Naturkund der Humboldt-Universität (MNHU), Berlin, Germany; The Natural History Museum (BMNH) London, U.K.; and/or original descriptions and illustrations.The terminology used for protoconch description followed STREBEL (1910).
The morphology of shell, jaw, radula and reproductive system was based on the methods used by JURBERG et al. (1988) and SALGADO & COELHO (1995).Photographs were taken with a digital camera and electronicmicrographs on S.E.M. Colors were codified according to KÜPPERS (1979).
Thaumastus (Thaumastus) lundi sp.nov.Diagnosis.Shell oval-elongated, 6 8 1 -7 whorls; protoconch with wide and depressed nucleus, 2½-3 whorls; aperture ear-shaped.Radula with 32 lateral teeth in one transversal row and jaw with 15-17 plates.Ovariotestis with six follicle groups; phallus retractor muscle wide and pleated, attached to the proximal part of flagellum; deferent duct emerging on the same level as the bifurcation of bursa duct and free oviduct running over and then under the muscular sheath, making a narrow loop and returning attached to the phallus.

DISCUSSION
Thaumastus (Thaumastus) lundi sp.nov.and T. (T.) taunaisii are similar by having the shell with elongated shape, standard of striae in the protoconch, brownyellowish color and thickened peristome.Regarding the reproductive system, they share the same course of deferent duct over the phallus muscular sheath and distal attachment of phallus retractor muscle.