826 REVIEWS 
(b) Diabase-serpentine group, early Cambrian to late Silurian; (c) Granites, 
intrusive, late Devonian; (d) Later dikes. II. The Alkaline province of 
the Monteregian hills described by Adams. ; Co NW awe 
Investigations Relating to Clays. By the UNITED STATES GEO- 
LOGICAL SURVEY in 1905. (Extract from Bulletin No. 285, Con- 
tributions to Economic Geology, 1905.) 
Contains: ‘‘Clays of Garland County, Ark.,” by Edwin C. Eckel; 
‘“‘Clay Resources of Northeastern Kentucky,” by W. C. Phalen; ‘Clays 
of Western Kentucky and Tennessee,” by A. F. Crider; ‘‘Clays of the 
Penobscot Bay Region, Maine,” by E. S. Bastin; ‘‘Clays of Cape Cod, 
Massachusetts,’ by Myron L. Fuller; ‘Notes on Clays and Shales in 
Central Pennsylvania,” by George H. Ashley; ‘‘ Bentonite of the Laramie 
Basin, Wyoming,” by C. E. Siebenthal. Caw W: 
The Eurypterus Shales of the Shawangunk Mountains in Eastern 
New York. By JoHN M. Crarxke. Bulletin 107, N. Y. State 
Museum, pp. 295-310, plates 1-8. Albany, N. Y., 1907. 
This important little paper gives conclusive paleontologic evidence for 
transferring the stratigraphic position of the Shawangunk Grit from the 
base of the Silurian to the Salina. C. A. Hartnagel had already reached 
the same conclusion from stratigraphic studies. His views are presented 
in another paper in the same bulletin. CW We 
Geology oj Diamond Head, Oahu, Mokokea Caldera. By C. H. 
Hircucock. (Bulletin of the Geological Society of America, 
pp. 469-96, plates 59-66.) Rochester, N. Y., 1906. 
“Diamond Head is a tuff cone thrown up explosively from beneath the 
level of the sea, and is to be compared with the Monte Nuovo, near Naples. 
It was ejected. through fossiliferous limestones of Tertiary age, probably 
Pliocene.” 
Mokokea Caldera is on the southwest slope of Mauna Loa. The order 
of events in its history is given, including recent eruptions. 
’ C. W. W. 
