191 



A THIRD REPORT OX HELICOID LAXD-SHELLS FROM JAPAX 

 AXD THE LOO-CHOO ISLANDS. 



By G. K. Gude, F.Z.S., etc. 



Read 11th January, 1901. 



PLATES XIX-XXI. 



Since the publication of my two previous papers (ante, pp. 8 and 70), 

 a considerable quantity of undescribed material has been obtained by 

 Mr. Pilsbry and myself, descriptions of which have appeared in the 

 Proceedings of the Academy of Natural Science, Philadelphia, The 

 Nautilus, and the Annals and Magazine of Natural History. Dr. 

 Ehrmann and Dr. Mollendorff have also described some new forms 

 in the Zoologischer Anzeiger and the Nachrichtsblatt der Deutschen 

 JUalakozoologischen Gesellschaft . 



The new species described by myself in the Annals and Magazine 

 are now figured for the first time, with one of Mr. Pilsbry's. I have 

 also added figures of Trishoplita commoda, A. Ad., and Microcystina 

 labilis, Gould, two species not hitherto illustrated. 



These various additional forms have thrown light on the systematic 

 position of several of the species, and consequently certain corrections 

 of generic nomenclature are now made. Several species previouslj- 

 ref erred to Arnouldia (= Comdus) have been shown by Mr. Pilsbry to 

 pertain to Kaliella. Dr. Mollendorff has also indicated that several 

 other species hitherto classed under Arnouldia, Titrea, Crystallus, and 

 Polita belong to Microeystina. Mr. Pilsbry has moreover pointed out 

 that the name Arnouldia, proposed by Bourguignat in lieu of Comdus — 

 preoccupied in Mollusca by Bafinesque — must give way to Euconulus 

 of Bernhardt, which has precedence by seven years over Bourguignat' s 

 name. Several species previously placed in Ganesella appear to fall 

 more naturally under Jacobi's genus Trishoplita, established for the 

 reception of T Goodwini and T. pollens. 



In view of the many alterations and additions, I have thought it 

 useful to append a revised list. 



1. Yitbea microdiscus, Beinh. Kioto. Three specimens. 



2. Polita RADiATELLA,Beinh. Kashima. Nine specimens. Previously 

 ref erred to as a synonym of Zonitoides nitidus (ante, p. 17), on the 

 authority of Dr. Kobelt, but the specimens which agree with 

 Beinhardt's figures differ from that species. 



3. Microctstina sinapidiem, Beinh. Kashima, province Harima. 

 Twelve specimens. 



