1884.] Geology and Paleontology. 1037 
of the mountain giving way. There only remains the south- 
ern part, which has been cut in two from the very top, and forms on 
the north side a magnificent precipitous cliff more than 2500 feet 
high. In the place where the fallen part once stood there is now 
everywhere deep sea, in some places as much as 1000 feet deep. 
The ashes thrown out by the eruption must have been enormous, 
especially if we are correct in assuming that the brilliant sunsets 
are due to the finer parts suspended in the atmosphere. Within 
acircle of fifteen kilometers’ radius from the mountain, the layers 
of volcanic ashes thus ejected cover the ground from sixty to 
eighty meters thick. The known surface over which the ashes 
were ejected, as calculated by Dr. Verbeck, is 750,000 square kil- 
ometers, apart from other unknown areas where they also de- 
scended. He thinks that the finer particles, propelled by the wind, 
have made a journey round the world. The vapor was condens 
to water, and froze in the cold currents. The refraction through 
these innumerable ice crystals, Dr. Verbeck thinks, caused the 
beautiful and red glows of our phenomenal sunsets. He calcu- 
Jates that the quantity of solid substances ejected by the volcano 
was eighteen cubic kilometers. Dr. Verbeck and his staff thor- 
oughly explored the island last October, when the heat was so 
great as almost to stifle them. : 
trapezoidal. Ichthyorodulites conjectured to belong to twenty- 
two forms, mostly new, are also described. The volume con- 
cludes with descriptions of the carboniferous invertebrates, by A. 
- Worthen, S. A. Miller and others. Thirty-seven species of 
Poteriocrinus, and eighteen other crinoids, are en 
essrs. Wachsmuth and Harris describe Heteroschisma pes 
pw genùs and species of Blastoidæ, and two other speci 
: nstoids. The Asteroidea are enriched by the addition of Comp- 
aster formosus and Cholaster peculiaris ; b 
Tremataster difficilis, and the Echinoidea by Hybochinus spectabilis, 
a new Peristodomus and three species of Archzocidaris. 
even molluscan species are given. 
