XIII. ON THE SUPPOSED OCCURRENCE OF 



THE MIOCENE GENUS FOS S A RU LU S 



RECENT IN INDIA. 



By lyT.-Coiv. H. H. Godwin-Austen, F.R.S. 



In the Fauna of British India, Mollusca, Freshwater Gastropoda 

 and Pelecypoda, Mr. H. B. Preston, on page 78, places Bithynia 

 costigera, Kiister {= marginata , Chm.) in the fossil genus Fossar- 

 ulus, following Geoffrey Nevill in his " Hand-List," Vol. II, p. 42, 

 with a ? . Having recently been looking over Indian species of 

 Bithynia in my own and the Natural History collection this generic 

 position has been brought into question. It appeared to me to be 

 so impossible that a fossil genus of Miocene age and European 

 habitat should be still Hving in Peninsular India. I sought Mr. 

 BuUen Newton's kind help, and he was able to not only show me a 

 Fossarulus but the type of the genus from Dalmatia quoted by 

 G. Nevill. The first glance cleared up a great deal, and showed 

 how great was the difference between the Recent and Fossil shells, 

 in every important character. It is surprising that Nevill came to 

 the conclusion he did in 1884. He may have had grounds at the 

 time for doing so, certainly at the time he was at work he did not 

 have in Calcutta the type shell of Fossarulus to refer to. Mr. Preston 

 has perpetuated Nevill's determination, when the means of verifi- 

 cation were close at hand in the Natural History collection. 



To show the difference in question I give the original des- 

 cription of both the genus and its type. 



Fam. PALUDESTRINIDAE. 



Jahi-biicli ihv Kaiserlich-K'oniglichen Geologischen Reichsaiistalt, IVieii, 

 XIX, p. 361, pi, xii, figs. ya-c. 



" Fossarulus novum genus. Testa parva, subglobosa, rimata, 

 " longitudinahter nodoso-costata ; apertura late ovata, superne et 

 " ad basin effusa ; peristomate continuo, incrassato, duplicato." 



'' Type Fossarulus stachei, Miocene, Dalmatia. 



" Schale annahernd kugelig, fest, mit einer Nabelspalte 

 " versehen, aus 4 stark gewolbten Umgangen bestehend, von wel- 

 ''chen der letzte fast f der Gesammthohe einnimpt; obere Win- 

 " dungen mit 3, die letzte mit 5 kraftigen, geknoteten Langs- 

 ' ' rippen verziert ; Naht vertieft ; Mundoffnung breit eiformig, 

 ' ' oben und unten mit einem kleinen Ausguss ; Mundrander stark 

 ''verdickt, doppelt, zusammenhangend. Grossenverhaltniss des 

 " abgebildeten Exemplares : Hohe 7 mm. Durchmesser 5 mm." 



