rsa tits rae. . 
CONTENTS. 
Page 
Art. XII.—Examination of Mr. Alfred R. Wallace’s Modifi- 
eation of the Physical Theory of Secular Changes of 
Sgr Be a ee a ee ee 81 
XII = Communications from the _° Geological Survey, ; 
"Ro ocky Mountain division.—V. » Sanidines ete., in the 
Nevadite of Chalk Mountain, Colimudes by W. Cross. 94 
—Occurrence of the Lower oe oe Limestone in 
ivew Mexico by I". SeRineee <2... eee be eee 97 
XV.—The Mirinesots Valley in the as Age; by W. U vee 104 
AVL oe Drift in Montana and Dakota ; by C. 
cee AE he ne ea tt ee ee 12 
XVI = Giak ‘ial and Champlain Periods about the mouth of 
e Connecticut Valley—that is, New Haven 
Fc: by J. D. na. (With Plates Land II)---- 113 
XVII.—Supplement to Paper on the.“ Paramorphic Se 
of the Hornblende of the Crystalline Rocks of the North- 
a es ; by BR. D. Invine.... 130 
} ite (?), a glueinum age phos hate and 
c oride, ane ‘Oxford ae Maine; by W. ? HmpENn 
: NTOS 
- ip! iedecdes a new 
he gupta om sas Plates nr and WV) he 
of chemically-definite 
ts Ber and ian ae? ponies acid 
ph encanto pare tan 
