64 JOURNAL OF THE [April, 



some points of more than ordinary interest connected with 

 them. 



Mr. Weed has described — Botanical Gazette, xiv, 117 — the 

 vast diatom-marshes of the Yellowstone Natiohal Park, which 

 owe their origin to the fact that the water from the geysers is 

 highly charged with silica. 



The crude material appears to be composed of vast numbers 

 of diatoms, associated with the dried gelatinous matter, which 

 usually accompanies such deposits. The usual methods of 

 cleaning the diatoms by boiling in the mineral acids, however, 

 almost entirely fail with these deposits, for the reason that what 

 appears at first to be only the usual accompanying organic 

 matter is in reality silicious sinter. An attempt to get rid of 

 this by boiling the deposit in caustic potash resulted in the 

 destruction of the diatomaceous frustules, while the sinter itself 

 was scarcely attacked. 



The deposits are quite similar in regard to the character of 

 the species found, the largest forms, however, occurring in the 

 cooler waters of the Yellowstone Lake. 



This subject was discussed by Mr. E. A. Schultze and Dr. N. 

 L. Britton. 



Mr. Kain donated the five slides of his exhibit to the Cabinet 

 of the Society. 



PUBLICATIONS RECEIVED. 



The Microscope : Vol. IX., Nos. 10, 12— Vol. X., No. 2 (December, 1889, 

 February, 1890). 



The American Monthly Microscopical Journal : Vol. X,, Nos. 10, 12 — 

 Vol. XI., Nos. I, 2 (October, 18S9— February, 1890). 



The Microscopical Bulletin and Science News : Vol. VI., No. 6 (December, 

 1889). 



Anthony's Photographic Bulletin: Vol. XX., No. 23 — Vol. XXI., No. 5 

 (December 14, 1SS9— March 8, 1890). 



Entomologica Americana: Vol. V., No. 10 — Vol. VI., No. 3 (October, 

 1SS9 — March, 1^90). 



Psyche : Vol. V., Nos. 160-166 (August, 1889-February, 1S90). 



Insect Life : Vol. II., Nos. 5-8 (November, 1889-February, 1S90). 



Bulletin of the Torrey Botanical Club: Vol. XVI., No. 12— Vol. XVII., 

 No. 2 (December, 1889-February, 1890). 



The Botanical Gazette : Vol. XIV., No. 12— Vol, XV., No. i (December, 

 1889-January, 1890) 



