616 THE AMERICAN NATURALIST. 
Aftet discussing a large number of analyses of the altered and the 
unaltered rocks, the author concludes that it cannot be proved that 
transfer of soda from the igneous rock to the sedimentary ones has 
taken place. The paper closes with a protest against ascribing to 
dynamic-metamorphism many of the effects that may be due to 
contact action. 
Notes. — The “ porphyritic gneiss” of New Hampshire, formerly 
supposed by Hitchcock and others to be a Laurentian metamor- 
phosed sediment, is shown by Daly! to be an igneous rock intruded 
into the surrounding rocks in post-Devonian time. Iwasaki’ men- 
tions the existence of a diorite dike cutting the Tertiary rocks in the 
Usui Pass, near Tokio, Japan. It consists of zonal plagioclase, horn- 
blende, quartz, and several accessory and secondary constituents. 
The author calls it an andendiorite, following Stelzner, who has 
described a quartz-bearing mica diorite occurring in a “neovolcanic 
dike” in Argentine. 
Two interesting examples of contact action are described by 
D’Achiardi.2 The first is between dolomite, on the one hand, and 
granite and diabase on the other, near Berdiaouch in the Ilmen 
Mountains, Russia, and the second between limestone and granite 
on the Isle of Elba. The new minerals produced in the limestones 
by the contact action are not essentially different from those occur- 
ring under similar conditions elsewhere.. The development of antigo- 
rite, pyroxene, wollastonite, and white mica is especially prominent. 
W. S. BAYLEY. 
1 Journ. of Geol., vol. v, pp. 694, 776. 2 Jb., vol. v, p. 821. 
3 Atti della Soc. Tosc, d, Sci. Nat, Pisa. Memoire, vol. xvi. 
