Japanese Land- Snails. \\ 



Shikoku, and Kiushiu remained connected until very recent 

 time, and have been separated within the life of those slightly 

 differentiated races which we term " subspecies." From 

 southern Kii, through Awaji and Shikoku Islands, across 

 Bungo Channel to Kiushiu, and westward across the lower 

 end of the Inland Sea to the west end of Hondo, must have 

 been a continuous land-area since Pliocene and down to 

 geologically recent time. Not only numerous species, but 

 mere races of more widely spread species, occupy this area, 

 and such a distribution is quite inexplicable except upon the 

 theory that the areas in question, though now separated, were 

 until recently a unit geographically, as they still are faunally. 

 There are doubtless species existing on Shikoku Island which 

 do not extend beyond its limits ; but the local differentiation 

 is not greater than upon an equal area of Hondo and does 

 not make against the view just set forth. 



In respect to classification and generic nomenclature, the 

 Japanese Zonitidae are in great confusion. Rein hard t, many 

 years ago, referred the species known to him to European 

 groups of the family. Early last year I recognized the f ict 

 that the Japanese Zonitidse belong mainly to Oriental, not 

 European genera. This opinion found expression in articles 

 published in August (vi. p. 382) and November (xv. p. 81), 

 in which I referred various species to the Oriental genera 

 MacrochJamys and Kaliella, showed that the name Euconulus, 

 Keinh., must replace the names Conulus and Arnouldia, and 

 expressed my belief that the Japanese species referred to 

 these groups really belong to Kaliella. Dr. v. Mollendorff, 

 in an article just published (xxi. pp. 35, 37), has reached 

 conclusions in part anticipated by my papers, in part at 

 variance with them. He has referred numerous species to 

 the genus Microcystina of Morch, most of them, I think, 

 incorrectly. The establishment of Microcystina upon an 

 adequate basis we owe to Godwin- Austen, who showed that 

 it is characterized by a callous thickening or flexure of the 

 columella. Of the Japanese species known to me by speci- 

 mens, only Arnouldia ceratodes, Gude, has this feature. I 

 consider v. Mb'llendorff s reference of this species to Micro- 

 cystina justified. The species Doenitzi, sinapidium, and 

 Hirasei of his Microcystina list have the shell-characters of 

 Macrochlamys, and not of Microcystina. Most of the other 

 species he mentions are known to' me, as they are to him, by 

 the descriptions only, and their generic reference is little 

 better than guesswork. 



Gastrodontella, Mollendorff, a new genus proposed for 

 G. japonica, Mlldff. (1901), a synonym of Kaliella multi- 



