60 The Ahierican Geoloffisf .iniv, i8% 
J. S. Diller. This Oregon lake, occupying a roughly circular 
pit nearl}^ six miles in average diameter, on the summit of the 
("ascade range about midway between mount Shasta and 
mount Hood, is of intense interest and beauty. The lake is 
(),239 feet above sea level and is reputed to be the deepest 
fresh water lake in America, having the remarkable depth of 
2,000 feet. It is surrounded by steep and precipitous clilfs, 
which rise in places over 2,000 feet above the lake, and are 
composed of sheets of lava and fragmental volcanic material 
dipping away from the lake. It is thought that the pit, in 
which the lake is situated, was formed b}' the sinking of the 
main mass of a huge volcanic mountain which once rose 
several thousand feet above the place now occupied by the 
lake. 
Academy op Natural Sciences of Philadelphia. May 19, 
1896. Mr. Henry A. Pilsbry spoke of the geology of the de- 
posits containing fossil Unionidie at Fish Neouse, N. J. The 
mussels, some twelve species of Um'o and Attodoiifa, occur in 
a thick black clay stratum used for brick and cile making. 
Below this is a stratum of red clay, gravel and " iron-stone" 
(bog iron) about two feet thick, which rests on a bed of sand 
of unknown depth. This sand shows the stratification and 
oblique lamination characteristic of arenaceous deposits in 
running water. The speaker considered that the hypothesis 
of our ancient " ox-bow" of the Delaware river explained the 
phenomena presented; the underlying sand having been tie- 
posited in the bed of the river; the channel was then aban- 
doned for a new one, leaving a lagoon or " slough" in which 
the layer of yellow material was deposited at subsecpient 
times of freshet and after the up-stream end of the lagoon was 
entirely filled up, the black clay w-as formed in idle water, 
largely by the decay of organic matter, molluscan and other 
life flourishing in lagoons of this nature, Mr. Pilsbry held 
that the black clay and underlying sand were a deposit 
wholly different in genesis and earlier in time than the gravel 
which overlies the clay bed, this last gravel being referred by 
professor Salisbury to the Pensauken formation. Besides tiie 
mussels, fossil wood occurs in the black clay, as well as 
remains of the Pleistocene horse, Equus major Leidy. The 
latter, as well as the Unionidne (some of which are recent 
species) prove the deposit to be of post-Pliocene age, instead 
of Cretaceous as claimed by Dr. Lea, Prof. Whitfield and 
some others. 
The character and age of the deposits were farther consid- 
ered by Prof. Heilprin and Mr. Woolman. 
May 26, 1896. Mr. ¥,d\\. Goldsmith reported that a speci- 
men of supposed geyserite from Hawaii had been found b}^ 
him to be an amorphous, soluble sulphate of lime. The sub- 
