FOR THE ADVANCEMENT OF SCIENCE. 561 
not visible, and in their stead extinct shells are abundant. Professor 
Agassiz has declared that the Amazon clays are “ drift" from the Andes 
transported by glaciers and ground down to an impalpable powder. But 
these fossils, some of them very delicate, are marvelously well preserved. 
Two explanations of the existence of saya fossils have been given: (1) 
That they are accidental, being fragments of some formation elsewhere, 
mingled with the drift. But this hypothetical formation cannot be found. 
x e 
not be later than the Pliocene. Moreover, the terraces which would re- 
sult from submergence are not discernible within or on the borders of 
the valle 
Professor Orton then alluded to the glacial transmigration hypothesis, 
ite t 
Andean highlands, that there had been no mingling of plants such as 
would have resulted had a vast glacier covered the whole or even the 
greater part of North America. And the conclusion reached was that 
facts were incompatible with the existence of an equatorial glacier and 
even of an intertropical cold epoch.* 
Mr. UR W. Ray — United Stat es Commissioner of Mining, gave a 
cific slope. The speaker, to save the time of the meeting, condensed 
em vts rapid talk the substance t his "e papers on ** The Lava-ducts 
— epee 575 “ The Great Salt Marsh of panes Peak,. 
hanes Ney The mer, he said, was a picture from the heart 
of the great prec ptione of the North, and the latter an equally 
characteristic scene from the region of solfataric and thermal-aqueous 
metamorphosis in the South. The accumulation of ice in the subterra- 
nean lava- euni the disappearance in them of streams (“lost r rivers”), 
various other features were eet vente to. The speaker ascribed 
ihe ikalia deposits of the Ne Bs n to the decomposition of the 
soda-felspar abounding in the rocks, "ea means of hot gases and waters, 
Professor C. H. Hrrcucock presented a paper upon ** The Geology and 
Topography of the White Mountains." The topographical results were 
embodied in a model which he exhibited — a raised model on the scale of 
three-fourths of an inch to one thousand feet. This model is about four 
b aes fossils aboye €— were given to PE. Conran for RES nein He eee eia 
Seven extinet, I , of which only three are no: 
nted. The species are 7saca Ortoni, I. lintea, Liris daga ee don crassilabra, E. Mis: 
paea sulcatus, Dyris gracilis, Neritina Ortoni, Bulimus — Pachydon (Anisothyris) 
tenuis, P. carinatus, P. mih wus, P. Mid P. a ete. F. vafa $, P. altus, and a bivalve allied 
to Mulleria, Duplicates f Professor Orton. 
