ontjjIiT Picrastojiinil |aiinnil |amnirg l, 1871. 



CONTENTS OF No. XXV. 



Art. Page 



I. Note on FLUOEESCENCE v. PSEUDO-DICHEOISM. By 



the late Eev. J. B. Eeade, F.E.S., P.E.M.S 1 



II. Notes on the Minute Structure of the Scales of Certain 



Insects. By S. J. Mclntire, F.E.M.S. 3 



III. On an Optical Illusion Slide : Cracks in Silica Films. By 



Henry J. Slack. F.G.S., Sec. E.M.S 14 



IV. Object-glasses and their Definition. By F. H. Wenham, 



Vice-President E.M.S 16 



V. On the Mounting of the Diatom-prism. By F. W. Griffin, 



Ph.D 24 



VI. On Pterodina valvata: a New Species. By C. T. Hudson, 



LL.D 25 



Progress of Microscopical Science 

 Notes and Memoranda 

 Correspondence 

 Proceedings of Societies ., 

 Bibliography 



30 

 37 

 38 

 39 

 44 



The Monthly Microscopical Journax is furnished free to Members of the 

 Eoyal Microscopical Society. Non-Members can get it from any bookseller, 

 price Is. 6d. per month. 



Contributors must write their Names and Addresses on the first page of MS. 



All Communications to be addressed to the Editor, 192, Piccadilly. 



