Reviews—Tertiary Mollusca, New Zealand. 231 
The complex of fiord channels and valleys is shown by the 
geological maps, especially by that of the Kasaan Peninsula, to be 
quite independent of the older grain of the country; the arrangement 
of the fiords is inexplicable on any theory of glacial erosion, and 
is only explicable by their origin along intersecting Upper Kainozoic 
fractures. The ore deposits are numerous bodies of copper ores in the 
contact zone, where granite has been intruded into limestones. The - 
ores occur in shoots, which though near the contact are not exactly 
along it. ‘The memoir is a valuable addition to the economic geology 
of Alaska. 
VIII.—Revision or tar Tertiary Motiusca or New ZrALaND, BASED 
on Type Marertat. By H. Sorer. New Zealand Geol. Surv. 
Pal. Bul. No. 3, pt. ii, 1915. pp. vii, 69, with 9 plates. 
\ R. HENRY SUTER, the consulting paleontologist to the 
il Geological Survey of New Zealand, has completed his useful 
redescription of a series of types of New Zealand Kainozoic Mollusca 
of species founded by Hutton, Mr. EK. de C. Clarke, Dr. J. A. Thomson, 
and Professor Marshall. He has established one of McCoy’s list 
Names as a new sub-species. ‘The revision is illustrated by nine 
excellent plates. The species range from the Miocene to the 
Pleistocene; the majority are Pliocene. Mr. Suter accepts the 
Oamaru Beds as Miocene, which is consistent with the conclusicns of 
McCoy and Chapman as to the age of the corresponding fauna in 
South-Eastern Australia. On p. 37 he, however, leaves the Australian 
range of Bathytoma haasti as Kocene, whereas from the localities 
cited it would also be more correctly included in the Miocene. 
IX.—Tue Inorcanic Constituents or Ecarnoperms: By F. W. 
Crarke and W. C. Wueeter. U.S. Geol. Surv. Prof. Paper 
No. 90L, 1915, pp. 191-6. 
ESSRS. CLARKE AND WHEELER have extended their 
interesting researches on the composition of the Crinoid skeleton 
to the KEchinoids and Stelleroids. ‘hey find by nine analyses of 
Echinoid plates that the amount of carbonate of magnesium in the 
shell ranges from 6 to 134 per cent, and that the geographical 
distribution of the specimens shows that the proportion of magnesia is 
inversely to the latitude. A series of analyses of the joints of the 
Starfish and Ophiuroids shows the same conclusion ; the proportion of 
magnesium carbonate ranges from 7:79 to over 14 per cent, and as 
a rule the proportion is highest in specimens from the warmest seas. 
A limestone therefore formed of the remains of Echinoderms which 
had grown in a warm sea would give rise to a magnesian limestone. 
The authors announce their intention of extending their investigation 
to other marine invertebrates to determine whether their skeletons 
show the same distribution of magnesia, so that magnesium sediments 
would naturally be deposited more in warm than in cold climates. 
