206 LAND AXD FRESHWATER 



and it is most, difficult when this occurs to spread them out again, 

 rendering counting impossible. The teeth are more numerous in 

 this radula and more minute than in any I have seen hitherto ; they 

 are in form of similar typo to those of Durgella leuicida and mai- 

 rangensis, of Tenasseriin and the Khasi Hills respectively, but still 

 closer to the outermost teeth of Lamprocystis sumhaensis, G.-A. 

 (vide Vol. II., Plate LXXIX. fig. 8 />), which points to this last 

 genns having a position rather with the subfamily Durgellinse than 

 any other. 



The Sarasins give figures of the teeth of Lamprocystis matin- 

 angensis and macassarica : the outermost teeth are serrate below the 

 terminal cusps ; this is also the case in Helicarion idee, Pfr., cele- 

 bensis, Pfr., adoJphi, Btittg., and mincdiasso', Kob. In the shells of 

 these two sets the only diff"erence is in regard to the number of 

 Avhorls, the shells of the first Lamprocystis being small and closer 

 wound. 



This interesting species of Durgella occurred among a small but 

 very well preserved collection of land-shells made and sent home to 

 the Natural History Museum by Dr. G. Rogers, after whom I have 

 the pleasure of naming it. I have also to thank Mr. Edgar Smith 

 for kindly letting me examine some of the valuable material. 



In connection with the position assigned to some Japanese land- 

 shells in MacrocMamys, a genus which occupies so many pages of 

 this work, and having considerable doubt as to this genus, strictly 

 defined by internal anatomy, extending to this part of the world, 

 I asked Mr. Hirase, of Tokio, to send me some examples preserved 

 in spirit. He very kindly responded to my request, and the result 

 has been exceedingly interesting as regards not only one but two 

 genera. 



The three specimens I received were from South Formosa, labelled 

 respectively Macrocldamys formosana var. hypografta, Pilsbry & 

 Hirase, ilf. fidgens, Gude, and Helicarion hiraseanus, Pilsbry. The 

 last is, as I shall show further on, so intimately connected with an 

 Assam species, that in spite of Formosa being so far outside the 

 original scope of this work, I feel it is necessary to describe and 

 figure all three in this Part. 



The record of species confined strictly to some particular State or 

 States has a certain amount of interest, and is useful to collectors, 

 but the exact range of genera, go far as they can be traced, is of 

 far greater importance and of absorbing interest ; and in this con- 

 nection it is impossible not to stray occasionally far beyond the 

 limits of British India. 



