1892.] NEW-YORK MICROSCOPICAL SOCIETY. 53 



The Corresponding Secretary read a communication from 

 Mr. K. M. Cunningham, dated Mobile, Alabama, December 4th, 

 1891, donating slides and material to the Society as follows : 



" The slides and rock specimens are sent with the view of i ut- 

 ting on record some new discoveries in microgeology of this char- 

 acter. Some years ago I donated a thin section of an indurated 

 silicious sedimentary rock which I regarded as a tripoli, as the 

 specimen seemed to show innumerable spicular spaces filled with 

 air. I also sent smoothed specimens to exhibit the superficial 

 aspect as opaque objects. I even then suspected that the rock 

 contained polycistinous bodies. While in Meridian, Miss., dur- 

 ing last October, I secured additional specimens of the rock, 

 varying in density. A few days ago it occurred to me to test 

 what I could find in the way of remains of Microzoa in the 

 softer and chalkier specimens. I brushed down in water the 

 surfaces of three different pieces, and was gratified by finding 

 Polycistina and curious sponge spicules, gemmules, and plates of 

 silex containing acicular inclusions. In pursuing this work I 

 made the experimental slides sent to the Society, and on each 

 slide I have noted with a small dot of India ink the situations of 

 various specimens of Polycistina. About seventy-five organ- 

 isms are shown. 



" In the rock specimens sent there are three grades of hard- 

 Tiess, and the two soft specimens were used by me in securing 

 the specimens on the slides. The material occurs in great stra- 

 tified beds with horizontal planes, which are shown very nume- 

 rously in Clarke Co., Miss., north of Enterprise, in the deeper cuts 

 of the Mobile & Ohio Railroad. 



" Some years ago, in attempts to make magnifying glasses, I 

 gave the optical polish to the lenses with this same tripoli stone 

 scraped to a fine flour. I believe the slides will demonstrate 

 something entirely new in the microscopical material line, as I 

 have reason to believe that the composition of this rock had 

 not been previously determined under micro-analysis by anyone 

 even in the State of Mississippi." 



On motion the thanks of the Society were tendered Mr. Cun- 

 ningham for these donations. 



The President, Mr. P. H. Dudley, delivered his Annual Ad- 



