Submitted by Alberto Vieira (martins_vieira@ibest.com.br) on 2017-10-18T19:54:20Z No. of bitstreams: 1 200448.pdf: 9734009 bytes, checksum: 65dfd2cb6e2c64d1e82c29c2a3d06c10 (MD5) / Made available in DSpace on 2017-10-18T19:54:20Z (GMT). No. of bitstreams: 1 200448.pdf: 9734009 bytes, checksum: 65dfd2cb6e2c64d1e82c29c2a3d06c10 (MD5) Previous issue date: 1984-08-23 / Estuda a anatomia de Laevapex diaphanus (Haldeman, 1841) comparando-a com Laevapex fuscus (Adams, 1841). L. diaphanus distingue-se de L. fuscus por possuir dente raquidiano com mesocones assimétricos, a vesícula seminal, a próstata e o ovoteste são menores, a pigmentação do manto é menos pronunciada. Laevapex distingue-se claramente dos gêneros sul-americanos por possuir eixo mediano de pigmentação tentacular, complexo peniano sem flagelo, com ultra-pênis desenvolvido e pênis de poro lateral. As interrelações com esses gêneros são discutidas. Pela primeira vez Laevapex é citado para o Brasil. / This study deals mainly with the anatomy fo Laevapex diaphanus (Haldeman, 1841), in comparison with Laevapex fuscus (Adams, 1841). L. diaphanus maybe distinguished from L. fuscus by the asmymmetric central tooth in the radula, smaller seminal vesicle, prostate and ovotestis , less pronounced mantle pigmentation The structure of the penial complex without flagellum, with a well-developed ultra-penis and lateral penis pore, and a conspicuous hollow core of black pigment in'the tentacles, distinguish Laevapex very clearly fron the south America genera. The interrelationships between Laevapex and these genera are discussed. The genus Laevapex is recorded for the first time in Brazil.