1887.] NEW-YORK MICROSCOPICAL SOCIETY. 39 



4. Sections of Felspar, perpendicular to, and parallel with the 

 lines of cleavage : by T. B. Briggs. 



5. Wood of the Maple (Acer), with the structure much 

 broken down by decay, but beautifully showing the plates of 

 the medullary rays, and certain of the hard longitudinal cells ; 

 by reflected light : by M. M. Le Brun. 



OBJECTS FROM THE SOCIETY'S CABINET. 



6. Pyrite, showing free Gold, Grass Valley, California, 



7. Diatoms, from Santa Monica, California. 



8. Isthmia nervosa, on Algae, Monterey, California. 



9. Spicules of Sponge, from California. 



10. Sherzolite, from the French Pyrenees. 



11. Volcanic Glass, from the Sandwich Islands. 



12. Quartz, from inclosure in Muscovite, Grafton, N. H. 



13. Quartzite, from the Black Hills. 



Mr. C. E. Hanaman, F. R. M. S., Curator of the American 

 Postal Microscopical Club, being present as a visitor, on re- 

 quest, addressed the Society, giving information concerning 

 the operations of the Club. 



Meeting of June 17TH, 1887. 



The President, the Rev. J. L. Zabriskie, in the chair. 



Twenty persons present. 



Mr. C. S. Shultz remarked upon the Stage Micrometer ex- 

 hibited by him, and ruled by Prof. Wm. A. Rogers, dwelling 

 particularly upon the numerous difficulties met in operations 

 of this kind. 



Mr. P. H. Dudley followed with further particulars respecting 

 the Dividing Engine employed by Prof. Rogers, and the mode 

 of correcting errors in its practical working : also respecting 

 the comparative advantages and disadvantages of rulings on 

 glass and metal. In explanation of his own exhibit — the 

 Fasoldt Eye-piece Micrometer — he said, that the lines were ex- 

 ceedingly delicate, and spaced at a distance of 500 to the inch. 



Mr. E. B. Grove, in connection with the exhibit by Mr. F. W. 

 Leggett, maintained, regarding the motion of the ovipositor of the 

 Saw-flies, that their action was not direct, but with a twisting 



