THE VICTORIAN NATURALIST. 



61 



decision favourable to the method. The two flagella in a Uving 

 Protococcus were also shown with a half-inch objective of only 

 40° angular aperture, dark field illumination being employed, and 

 the border of the transparent cellulose envelope was also rendered 

 very obvious. Work was then undertaken by those present with 

 their own apparatus and objects, Mr. Shephard being assisted by 

 Mr. H. Grayson in the work of demonstrating the methods to 

 individual members. Among the objects examined was a section 

 of the sponge Leucandra echinata, prepared by Rev. W. Fielder, 

 which afforded some of those present their first view of the much- 

 described but rarely visible collars and flagella of the endoderm 

 cells. Mr. W. H. Archer, F.L.S., exhibited a very fine homo- 

 geneous immersion lens of the new semi-apochromatic type, 

 which gave very vivid pictures of the objects examined by it. 



The nature of the subject was somewhat foreign to those set 

 before members at these meetings, but of its practical value there 

 can be no doubt, and Mr. Shephard's clear exposition will 

 encourage many of those present to master a few of the methods 

 by which they will be enabled to examine with accuracy and 

 precision many details of interest and value to a microscopist, 

 which have hitherto been known to them only through the labours 

 of others, or, it may be, of unravelling some of those intricacies 

 of nature which it is the object of the field naturalist to note 

 and record. 



NOTES ON THE LAND AND FRESHWATER MOL- 

 LUSCA OF CASTLEMAINE AND NEIGHBOURHOOD. 



By F. L. BiLLINGHURST. 



Communicated by T. S. Hall, M.A. 



(Read before the Field Naturalists' Chib of Victoria, Sth May, 1893. J 



The study of this branch of natural history appears, as far as I 

 can learn, to have been somewhat neglected in Victoria, especially 

 in the up-country districts. Scarcely anything has been added to 

 our knowledge of this subject since Professor Tate published a 

 list with remarks on the " Land and Freshwater Shells of Vic- 

 toria," in the " Transactions of the Royal Society of South 

 Australia," vol. iv., p. 71. The number of species at present 

 recorded from the colony is comparatively small, but there is no 

 doubt we possess many forms which have not yet come under the 

 notice of our very limited number of collectors. I have ap- 

 parently met with two such here already, and it is very probable I 

 shall yet come across more. A diligent search within a radius of 

 three miles of the town yielded me comparatively little. Our 

 Streams have been spoilt by mining operations, and our sandstone 



