THE AMERICAN 



MONTHLY 



MICROSCOPICAL JOURNAL 



Entered at the post-office as second-class matter. 



VOL. XXI, OCTOBER, 1900, NO, 10, 



CONTENTS. 



Hyalodiscus in the Neocene Deposit. Edwards 271-275 



Amoeba Having No Vitality. Edwards 275-279 



A New Exhibition Microscope. 279-280 



On the Metallography of Iron and Steel Merritt 280-287 



Malaria and Mosquitos. Ross 287-290 



The London Microscope. Beck 290-292 



A New Method of Counting White Blood Corpuscles. KourlofF. 292-293 



Universal Sizes. R. M.S. 294-295 



Notes bY J. H. Cooke. — Blood ; Warm Slides ; Water Baths... 295-297 

 Notes by Shillington Scales. — Material for Botanical 



Study ; Mounting 297-298 



Hyalodiscus in the Neocene Deposit. 



ARTHUR M. EDWARDS, M. D. 



For many years I have suspected that that beautiful 

 Bacillarian Hyalodiscus subtilis which J. W. Bailey des- 

 cribed and named could be fouod if looked for in the fos- 

 sil state. Bailey found it, it will be remembered, on algae 

 growing at Halifax, Nova Scotia. I have now found it in 

 that problematical rock, the Neocene of California. This 

 ig called the Miocene Tertiary by the older geologists. 

 Therefore, 1 wish to clear up the synonomy of that form 

 and, at the same time, to furnish what I know of its hab- 

 its. Just after Bailey died, he left his collection to the 

 care of the Boston Society. This society gave me the 

 leave to examine it and when in Boston I did so. Before 



