- 
358 Scientific Intelligence. 
of a synthetic type, which united the characteristics of the Orthoptera 
and Neuroptera, in themselves closely allied; this point h es 
atient and severe investigation, and only my earliest impressions are 
here recorded, made, however, immediately after a close examination 
into the relations of other fossil insects. 
eon the Azoic age and metamorphic origin of the Iron Ore of 
Mexico, described by N. S. Manross, at page 309 of this volume; by 
J. D. Dana.—The great thickness and extent of the magwetic and spec- 
ular iron masses of Guerrero leave little doubt that the rocks belong, 
like those of Northern New York, Michigan and Canada, to Azoic or 
presilurian time, and thus they indicate the existence of an Azoic area 
in this part of the continent. The metamorphic nature of the iron ore 
is proved by the alternation of the beds with conformable layers or strata 
of granular or metamorphic limestone, and syenite or granite. Ina sec- 
on either side there are alternate beds of iron ore and syenite with < 
by F. B. Meex. Smithsonian Miscellaneous Collections. 32 pp. 8v 
Washington, Nov. 1864.—This list of Invertebrate Miocene Fossils of 
North America is complete to the time of publication, both as regards 
paleontological discovery, and zoological science. Critical remarks are 
appended to the list. 
10. Ichthyosaurian Skin.—A specimen of the Ichthyosaurus t _ 
of the Royal Geographical Society, Sir R. I. Murchison, contains @ dis- 
cussion at length of the question of the European drift, in ja 
uthor sustains the Iceberg theory. Only the want of space preve? 
our citing his views in this Journal, 
