336 PROCEEDINGS OF THE ACADEMY OP 



Gray for hie exertions in securing for the Society the herbarium of 

 the late Dr. Short, of Louisville, Ky. 



' Dec. 8th. 

 Dr. Carson, in the chair. 



Twenty members present. 



The following paper was presented for publication : 



"On some new and singular intermediate forms of Diatomacese.'* 

 By F. W. Lewis, M. D. 



Dr. Morris mentioned that a nest of owls, Strix pratincola, had been 

 found in the turret of a church on Rittenhouse Square. 



Dec. 15th. 



The President, Mr. Lea, in the Chair. 



Thirty-two members present. 



The following paper was presented for publication : 



" Synopsis of the Species of Hosackia." By Asa Gray. 



Dec. 22d. 



The President, Mr. Lea, in the Chair. 



Sixteen members present. 



The following was presented for publication : 



" Synopsis of the Echinoids collected by Dr. "W. Stimpson." By 



A. Agassiz. 



Dec. 29th. 



The President, Mr. Lea, in the Chair. 



Twenty-nine members present. 



On report of the respective Committees, the following papers were 

 ordered to be published in the Proceedings : 



On some New and Singular Intermediate forms of DIAT0MACE2E. 

 BY F. W. LEWIS, M. D. 



About three years ago I made a gathering from the marsh bordering a 

 shallow pond, situated in the Notch Valley, (White Mountains,) from the 

 Southern end of which the Saco river takes its rise. This pond is fed by 

 numerous mountain streams of small size, which nearly always dry up during 

 the heats of summer. Its principal source of supply is in the springs which 

 well up from beneath the morass, in the centre of which the pond lies. 



This gathering was principally composed of particles of the adjacent rocks, 

 mixed with some vegetable debris. It contained both Diatornaceas and Des- 



[Dec. 



