69 



JPaludinella (Pfeiffer), one of the family Assimiiiiidc^ ; but 

 tlie shell in that case is umbilicate, and the eyes of the animal 

 are on the middle of the tentacles. 



But should the genus be called Hijdrohia ? Clearly not ; 

 because, as we have seen, this is meant to include marine 

 shells, while ours are entirely fluviatile. Bijiliinella seems 

 the only genus under which they can be ranged — that is, of 

 course, if our species are similar to those described by Mons. 

 Moquin-Tandon, from France. Some of our species differ 

 in a remarkable degree, as I shall specify hereafter ; but in 

 the meantime I shall regard the majority as Bythinella. 



In future, therefore, the shells inhabiting our fresh and 

 brackish water, marshes, and streams, which have an ajjpear- 

 ance like very small PaludincB, must be regarded as belonging 

 to the genus Bythinella. They are generally entangled in 

 the confervse or green slime which lines the sides of the 

 creeks and swamps, and sometimes in freshwater streams.* 

 They must not be confounded with the American genus 

 Amnicola, which has the axis of the shell perforate. 



I must further remark that, since preparing my mono- 

 graph, I have been able to consult Mr, John Brazier, and 

 examine the type specimens of the two species described by 

 him in the Zool. Froc. for 1871, p. 696, and named Faludes- 

 trinaLegrandlana Siiid. P. Wisemaniana. It will be remembered, 

 perhaps, that I said of them that I had been imable to find 

 either of the above shells, or anything like them. Mr, 

 Brazier was then in New G-uinea, and I could not communi- 

 cate With him. I find now that Faludestrina Lecjrandiana is 

 my Bythinia unicarinata, and the solid, stunted, hair-like 

 spines seen luider the lens, spoken of by Mr. Brazier in his 

 diagnosis, are the remains of the interrupted keel dpscribed 

 by me. Pcdudestvma Wisemaniana is, I believe, my Bythinia 

 tasmanica, which is common in all the creeks near Hobarton ; 

 but I think we should amend both descriptions by stating 

 that the suture is well impressed, not grooved. 



I find, also, that just before my paper was read to the 

 Society — that is, in July, 1875 — a paper was read by Mr. 

 Brazier, on March 29, 1875, before the Linnsean Society of 

 New South Wales, on some si3ecies of Australian and Tas- 

 manian land and freshwater shells. In this paper I find I 

 have been anticipated in some of my species. Mr. Brazier's 

 Amnicola Simsoniana is my Bythinia j^ontvillensis. My Pla^ 

 norhis tasmanica is Flanorhis meridionalis of Mr. Brazier's 

 paper. I need scarcely say that I had no opx:)ortunity of 

 seeing Mr. Brazier's paper, as it was not published until a. 



■^ River Jordan, at Brighton ; Derwent, at Dunrobhi. 



