190 JOURNAL OF THE [July, 



12. Arranged butterfly scales : by C. W. McAllister. 



13. Foraminifera from Bermuda : by W. G. DeWitt. 



14. Leaf of Onosmodium Carolinianum, showing curious pubes- 

 cence : by J. D. Hyatt. 



15. Palate of Patella vulgata (Limpet), showing teeth : by 

 J. D. Hyatt. 



16. Syndendrium diadema ; mounted by MoUer : by M. M. Le 

 Brun. 



17. Papyrus, transverse and longitudinal sections, from the 

 Nile : by H. W. Calef. 



18. Echinus spine, transverse section, by dark-ground illu- 

 mination with Zentmayer's Abbe Condenser : by C. S. Shultz. 



19. Sunstone— oligoclase spangled throughout with minute 

 scales of gold-colored mica — from the Greeley farm, Chappaqua, 

 N. Y. : by G. F. Kunz. 



20. Artificial Sunstone, or Venetian Goldstone — glass 

 spangled with brass filings : by G. F. Kunz. 



21. "File" of Katydid: by B. Braman. 



22. Spores of Eqiiisetuin : by B. Braman. 



23. A Portable Cabinet, accommodating one hundred 

 slides ; designed by Prof. Hamilton L. Smith : by Edward G. 

 Day. 



note on peridinium and asterionella. , 



Mr. C. S. Shultz : " I have observed for several years that 

 when the water-supply of New York or of other cities is per- 

 vaded with the gelatinous substance which gives it a fishy taste, 

 neither Peridinium nor Asterionella abounds in it. The abund- 

 ant occurrence of these forms accompanies and indicates a purer 

 condition of the water." 



hints on microscopical mounting. 



At the President's request, Mr. E. G. Day gave some hints of 

 his methods of microscopical mounting, as follows : — 



" Wax cells may be readily made by using a pair of dividers 

 about two and one-half inches long, furnished with a thumb- 

 screw and having fine steel points. You may with this instru- 

 ment cut from sheet wax a ring of any diameter, and by laying 

 ring upon ring you can build a cell of any depth. The wall of 

 such a cell may be punctured with a fine needle so as to allow 



