The taxonomy of the speciose genusGanesellaW.T. Blanford, 1863 and the endemic genusGlobotrochusHaas, 1935 is unclear since the anatomical characters of the the type species of these two genera have never been reported before. Therefore, the present paper provides the first anatomical descriptions of the reproductive apparatus, pallial system and radula ofHelix capitiumBenson, 1848 andHelix onesteraMabille, 1887, the respective type species ofGanesellaandGlobotrochus. In addition,Ganesella rhombostoma(Pfeiffer, 1861) andGanesella carinella(Möllendorff, 1902) from Thailand are re-described, and a new species,Ganesella halabalahSutcharit & Panha,sp. nov., from southern Thailand is described. This new species differs from all others by having a larger shell, an obtuse apex and an aperture lip with a prominent beak-like deflection.