10 proceedings of the academy of [1890. 



January 14. 

 Dr. Charles Schaeffer in tlie chair. 

 Tweuty-two persons present. 

 The death of J. Frank Kniglit, a member, was announced. 



Pea-like Phosphorite from Polk Co., Florida. — Mr. Edw. Gold- 

 smith stated that Mr. Jos. Will cox had received from Mr. E. R. 

 Childers of Fort Meade, Fla., a specimen of rock which, it is 

 stated, is about to be quarried for use as a fertilizer. The rock 

 extends over a considerable area of territory that is tributary to 

 Peace Creek, from the bottom of which stream a large amount of 

 what is supposed to be phosphate of lime is now obtained by two 

 companies operating there. It is essentially a phosphorite occurring 

 in pea-like masses mixed with carbonate of lime, fragments of bones 

 and shells, small pebbles of quartz and Limonite. Although the 

 rock is brittle, a thin section was prepared for microscopic examina- 

 tion. This was accomplished by Mr. Lancaster Thomas in a way 

 that is worth noting. The specimen was completely soaked with 

 boiled Canada balsam prior to the grinding. The result was a 

 transparent slide. There was observed, besides the above mentioned 

 mixture, amorphous silica in which were imbedded acicular crystals 

 of apatite. 



The si)ecific gravity was found to be 2-675. The rock cannot be 

 considered rich in phosphoric acid. The latter, however, appears 

 fairly disseminated through the whole mass. The pea-like globules 

 were tested separately, together with fragments of bone and the 

 dull brown-colored Limonite, phosphoric acid being found in each 

 case. A quantitative determination of the acid has of course com- 

 mercial interest but is out of the question here. 



The name proposed for the rock was suggested by the pea-shaped 

 globules. It may be considered as a variety of Phosphorite. 



January 21. 

 The Pi-esideut, Dr. Joseph Leidy, in the chair. 

 Nineteen persons present. 



A paper entitled " On the Anatomy of Aerope caffra Fer.," by 

 H. A. Pilsbry was presented for publication. 



January 28. 

 Mr. J. H. Redfield in the chair. 

 Thirty persons present. 



