os 
: 
. 
Geology and Mineralogy. 475 
0 become vapor toward its surface or in its outer portion. But 
the indications of moisture in the tra _of the ridges are not 
the AL a ior on -: she rap, rendering it siitor itic at ‘ahi 
expense of the pyroxene or pyroxene and feldspar. Oft ten a very 
small part only, if any, of a hydrous trap ridge is amygdaloidal ; 
the hydrous seve ae aioe te slong et the mass. And 
trap (sometimes sallod vacluphy fy, being fraqueatly the only 
kind. The feature is wae ie ent of pressure, and is a pre- 
requisite to the amygdaloidal. The distinction to which the 
observations of E. S. Dana seemed to lead was that the masses 
of the several trap ridges in Southern Connecticut became gradu- 
ally more and more chloritic, or hydrous, on going from west 
was a subordinate one, occasionally observed where ge pean 
tion was oe st. 
that he is “ by no means a scienti fate ? We believe this statement, 
and see little else in the paper to _ with so much confidence. 
The author informs his readers much that nobody else know 
Streams “ underneath the glacier,” “wild and turbid streams, 
ridge or back bone of the island; and their depth was so great 
that the water-worn stones were carried by the current—* not by 
the drift” - the top of Harbor Hill, the higshinet point of the 
island. [The greatest height according to the Coast Survey i is 
oe feet. | This ineredible fact is thought not to seem bahar 
when we remember that the glacier was from ten to 
ere feet in thickness,” and that “it was under the leis 
a these mighty torrents Lag ailed.” 
Relations of the ‘‘Felsyte” to the Co nglomerate on Central 
eeu Milton, Mass,, to the south of Bostou.—Professor M. E. 
Wapswortn has given the results of his observations on the 
Milton *“ felsyte” in the Harvard University Bulletin of October, 
1882. They differ widely from those of Professor W. O. Crosby 
in vol. xix of this Journal (1880). He states that the felsyte is 
only a somewhat pis 19 tion of the associated conglomerate. 
ains in some parts many argillaceous pebbles only Leer 
obliterated, and the two cores or aduate into one another 
