Taxonomical Study On A Sample Of Pulmonates From Santa Maria Da Vitória, Bahia, Brazil, With Description Of A New Genus And Four New Species (Mollusca: Orthalicidae And Megalobulimidae) Author Simone, Luiz Ricardo L. text Papéis Avulsos de Zoologia 2012 2012-12-20 52 36 431 439 http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0031-10492012021600001&lng=en&tlng=en journal article 10.1590/S0031-10492012021600001 1807-0205 13175196 EEA7C3F0-0F45-47E0-9C04-D14DA23BA6F4 Megalobulimus amandus new species ( Figs. 22-26 ) Types: Holotype MZSP 103917 . Paratypes : MZSP 103919 , 3 shells ; USNM , 1 shells; MNRJ , 1 shells; NMHN, 1 shells; MZSP 103918 , 10 shells; all from type locality . Type locality: BRAZIL . Bahia ; Santa Maria da Vitória , ~ 13°24’S , 44°12’W , ~ 460 m of elevation ( Coltro col., i/2012 ) . Diagnosis: Shell with less than 80 mm , tip pointed, spire acuminate. Protoconch bearing series of uniform, delicate axial cords. Shell walls relatively thick. Peristome simple, pink to red. Description: Shell up to 80 mm ; outline oval; apex acuminate; width ~60 of length, dorso-ventral height ~50% of shell length. Color mostly pale beige in periostracum-lacking specimens ( Figs. 22-25 ); some few specimens with periostracum ( Fig. 26 ) somewhat glossy, eroded, presenting mosaic of pale and dark brown bands randomly disposed axially; peristome red to pale pink. Protoconch of ~3 weakly convex whorls, forming a somewhat pointed dome with ~70°; first whorl mostly smooth, opaque, remaining whorls bearing much delicate, uniform, narrow axial cords, ~ 120 in last nepionic whorl ( Fig. 25 ); each cord running from suture to suture since second whorl, interval between cords very narrow; limit between protoconch and teleoconch barely clear, orthocline. Teleoconch of 2.2 to 2.5 whorls, first whorl with almost straight profile, last whorl more convex than preceding ones. Spite ~60% of shell length. Sculpture similar to that of protoconch, with cords becoming delicate, but well-marked undulations, ~ 60 in penultimate whorl; ~30% of specimens possessing hammer-like marks in last whorl mid-region ( Fig. 24 ) and region preceding peristome. Peristome complete, normally thick ( Figs. 22, 23 ), glossy, lacking tooth of folds; aperture elliptic, ~54% of shell width, ~50% of shell length. Outer lip simple and rounded. Inner lip feebly concave; no clear separation with callus and parietal region ( Figs. 22, 26 ). Umbilicus extremely narrow to absent. Measurements (in mm): Holotype : 78.9 by 50.0; paratype MZSP 103919: (1) 69.8 by 40.2; (2) 25.6 by 17.6. Distribution: Known only for type locality. FIGURES 15‑26: Shell of types and ordinary specimens: 15-20) Anostoma tessa new species ; 15) Holotype, apertural view (H 31.1 mm); 16) Same, dorsal view; 17) Same, left view; 18) Same, right view; 19) Same, detail of aperture, apertural-slightly anterior view; 20) Paratype MZSP 103915, apertural view (H 31.1 mm); 21) Rhinus suturalis, MZSP 103924, frontal view (H 23.6 mm); 22-26) Megalobulimus amandus new species ; 22) Holotype, apertural view (H 78.9 mm); 23) Same, right view; 24) Same, dorsal view; 25) Paratype MZSP 103919(2), young specimen, apical (larger) and apertural view (H 25.6 mm); 26) Paratype MZSP 103919(1), adult with thin lip, apertural and right views (H 69.8 mm). Habitat: Caatinga environment. Material examined: Types . Etymology: The specific epithet refers to the outline of the shell, resembling a drop. From the Tupi native language from South America, amanda or amana meaning rain or related to rain. Discussion: Megalobulimus amandus clear belong to the informal complex Megalobulimus oblongus (Müller, 1774) as introduced by Simone & Leme (1998) . This complex includes species with deciduous periostracum, peristome normally reddish, sculpture almost exclusively axial strong undulations, and a protoconch also only sculptured by clear axial, uniform undulations or narrow cords. This set of characters can be regarded as the definition of the genus Psiloicus Morretes, 1952 , in such M. amandus and remaining M. oblongus complex can someday belong after a deeper revision of the group. A conservative approach is given herein. Only few of the 62 valid species of Megalobulimus have pointed shell apex ( Bequaert, 1948 ; Leme, 1973 ; Simone, 2006 ). This is one of the main characters of M. amandus , as most Megalobulimus in fact possess a more rounded, dome-shaped apex. For this reason, M. amandus only needs to be compared with species from M. oblongus complex with pointed apex. M. amandus differs from M. formicacorsii (Barattini & Ledón, 1949) , from Uruguay , in having aperture wider and longer, sculpture shallower, and umbilicus narrower or absent. It differs from M. maximus (Sowerby, 1825) , from Amazon, in being much shorter and smaller, by shallower suture, and by reddish peristome. It differs from M. riopretensis Simone & Leme, 1998 , from São Paulo, in having narrower aperture, narrower shell width, by more delicate protoconch and teleoconch sculptures, and by less developed umbilicus. It differs from M. wohlersi Morretes, 1952 , from Mato Grosso do Sul, by narrower shape, more elongated aperture, shallower suture, broader spire, and more delicate sculpture. The megalobulimids from Northeastern Brazil normally possess a purple pigmentation in the protoconch and spire first whorls. This is not the case of M. amandus , which has uniform coloration. On the other hand, the species of that region are normally of small size for a Megalobulimus , i.e., below 80 mm , which is the case of the new species. Another interesting feature of M. amandus is the absence of folds and teeth in the peristome, even in more thickened specimens ( Figs. 23, 24 ). Tooth and folds in parietal callus or in middle level of outer lip are common occurrences in species from that region. A conservative approach is given here considering the genus Megalobulimus in Megalobulimidae Leme, 1973 . However, it is recognized that the taxon can possibly be a special branch of Strophocheilidae , and even Acavidae . A project on this matter has been developed, mainly considering phylogenetic methodologies.