1893.] Proceedings of Scientific Societies, 181 
apatite-bearing rocks to the surrounding gneiss. Two Neocene Rivers 
of California, Waldemar Lindgren, Washington, D. C. It wasthe pur- 
pose of this paper to briefly indicate the direction and grade of the 
principal forks of the Neocene equivalents of the present Yuba and 
American Rivers. These streams now drain an area in which many 
important Neocene gravel deposits are located, and to trace the old 
water courses is of the highest importance in order to successfully open 
and mine the auriferous channels. The results recorded here have 
been reached during the course of the investigation of the Gold Belt 
carried out under the direction of Dr. G. F. Becker, by the U. 8. 
Geological Survey. 
The geological events related to the accumulation and covering up 
of the Neocene channels were briefly sketched and the different systems 
of channels described. The fact was accentuated that the Neocene 
rivers closely correspond to those of the present day in the extent of 
their watersheds, although by no means always in the direction of 
their principal forks. A short statement was given of the work pre- 
viously done in the same field by other investigators. 
The course of the Neocene Yuba and American Rivers was des- 
cribed, by the aid of a map, on a small scale. In places where 
differing results have been obtained from those of other observers, or 
where new facts have been brought out, a more detailed statement was 
given. Practical results : The greater part of these Neocene channels is 
now covered by heavy masses of volcanic material and many of them, 
though auriferous, have not yet been opened for mining operations. 
The vontinuity of certain channels under the lava cap can be asserted 
and their approximate positions indicated ; some of them, most likely 
to prove remunerative, but which have not yet been opened up, were 
mentioned; among them are the Blue Tent Channel, the Long 
Canyon Channel, and the Webber Creek Channel. 
Boston Society of Natural History.—Dec. 21.—The follow- 
ing papers were read: Some New Experiments on the Absorption of 
Liquids by Aerial Parts of Plants, Mr. W. F. Ganong; The Abdom- 
inal Pouch of Butterflies of the Genus Parnassius, Mr. 8. H. Seudder; 
Columnar Structure in Stratified Rock, Prof. W. H. Niles. 
- January 4, 1893.—The following papers were read : Account of Some 
of the Botanical Establishments of Europe (photographs were shown), 
Prof. W. G. Farlow ; Application of the Microscope to the Study of 
Rocks (colored stereopticon views were shown), Dr. J. Eliot Wolff. 
SAMUEL HENSHAW, Secretary. 
