トルコのイスパルタ郡ウルボール町で発見した新種Vitrea politissimaを記載する。殻の形態から，本種は，本属の中で殻が大きく，殻臍が広いVitrea ernesti, V. ephesina, V. klemmiおよびV. sossellaiと近縁であると推定される。既知の分布情報を用いて本属の生物地理を解析した結果，地上に露出した岩石やその根元の地面に生息する岩石性の種は相対的に狭い地域に分布し，分布域が広い種は岩石性ではないことがわかった。岩石性の種の分布が狭いのは，生息に必要となる岩石が狭い範囲にしかないからではなく，分散力が低いからであると推定される。生物の体系，生物相，生態に関する研究の発展により地理分布のパターンとその形成プロセスを理解する上での有益な知見が得られることを本研究は例示する。
A rare terrestrial gastropod species, Japonia inouei, is newly recorded from Mie Prefecture, central Honshu, Japan. A living specimen was collected in Ogisu Valley, Suzuka City, in 2013. A brief morphological examination was carried out on this specimen, and compared with conspecific and allied species collected from adjacent areas. Five diagnostic characters were recognized in the present specimen: 1) two rows of petal-like periostracal hairs on the periphery of the body whorl, 2) blackish coloration of the head-foot, 3) a taenioglossate radula with relatively few cusps, 4) a grayish white penis with dully acute tip, 5) ball-like feces containing plant tissues in the intestine. Examination of additional specimens of J. inouei collected from the Kii Peninsula revealed that there is a considerable variation in the morphology of the petal-like periostracal hairs. Although the present specimen possesses distally expanding hairs with a smooth surface, most specimens from the Kii Peninsula possess similarly shaped hairs but with a striated surface. In addition, larger and more aged specimens from the Kii Peninsula tend to have narrower hairs, suggesting age-related change in their shape. However, a population from Kushimoto-cho comprises specimens of similar sizes with both wide and narrow hairs, and it is also probable that the difference may be ascribed to intraspecific variation. The present record represents a considerable north- and eastward range expansion of this species to Mie Prefecture. The lack of previous records in this area can be attributed to the fact that the morphology of the periostracal hairs is the only morphological character that distinguishes this species from its allies, and specimens possessing hairs in good condition are extremely rare, like the species itself. It is thus necessary to reconsider the distributions of this and allied species in the western part of Honshu, where more than two species are potentially distributed sympatrically, based on the careful examination of periostracal hairs.