304 The America?i Geologist. November, isow 
the smoke. The officers on board these ships were not able, foi 
two days, to take observations on account of the sun being ob- 
scured l)y the smoke. , 
On the 24th of August, a month after the lava had ceased 
Howing, fire was again seen on one of the cones. It was hardly 
more than a momentary flash however. The same thing was 
observed on the top of Mauna Loa two days before the erup- 
tions. Light appeared at the top of the mountain, disappearing 
in a few seconds. During the eruption, the summit of Mauna 
Loa was frequently covered with a light colored cloud. It is 
reported that this condition prevailed both before and after the 
time of eruption. 
REVIEW OF RECENT GEOLOGICAL 
LITERATURE. 
A Memoir on the Paleozoic Reticulate Sponges constituting the 
Family Dictyospottgidce. By James Hall in collaborati(m with John 
M. Clarke (University of the State of New York, Albany, 1899. 344 
pages, 70 lithograph plates, large 4to.) 
This volume is the final execution of a plan conceived by the late 
professor Hall to bring together in monograph form all obtainable 
facts pertaining to these ancient glass sponges for which he, many 
years ago, proposed the family name here used. The work is of 
especial interest as demonstrating the abundance, variability and biolo- 
gic importance attaching to what has been heretofore regarded an 
inconsiderable element of paleozoic faunas. The presence of seventy 
species of these organisms in the Chemung fauna of New York and 
Pennsylvania may startle students who have collected assiduously 
from these sea bottoms, perhaps without finding a trace of any. At 
that time, however, and during the deposition of the calcareous shales 
of the Keokuk group at Crawfordsville, Indiana, the glass sponges 
seem to have culminated. There were veritable sponge "plantations" 
in these early seas, and the authors have located several of these in 
the Chemung sediments, from some of which several hundred speci- 
mens of a given species have been taken. It is seldom that these 
plantations produce more than a single species, and in some cases 
the species seem to be restricted, each to its peculiar colony. The 
memoir opens with an introductory chapter treating of the general 
nature of the sponges, with especial reference to the silicious sponges, 
and in particular to the Hexactinellida, the order to which the Dictyo- 
sponges appertain. Following chapters are devoted to the spicular 
