REVIEWS . 717 
The report also contains much information concerning the fauna, 
flora, and timber resources of the district, and has appendices giving 
lists of elevations and catalogues of the Palaeozoic fossils. 
FRANK D. ADaMs. 
The Paleozoic Reticulate Sponges Constituting the Family Dictyo- 
spongidae. By JAMES Hay and Joun M. Crarke. 
More than a year ago volume one of the Fifteenth Annual Report 
of the New York state geologist made its appearance. In the introduc- 
tion to this report several papers were announced which were not 
included in the volume, one of them being a monograph of the 
Dictyospongidae. It is this monograph which has now been published 
as volume two of the report above mentioned. It also appears in 
another binding as Memoir II of the New York State Museum. 
Unfortunately the annual report of the state geologist does not con- 
tain the complete monograph, the descriptions and illustrations of Car- 
boniferous species being omitted. This monograph has long been in 
preparation by Drs. Hall and Clarke, and the printing of it had only 
been begun at the time of Dr. Hall’s death. 
The dictyospongidae are an extinct family of hexactinellid sponges, 
whose nearest living representative is the delicate glass sponge, 
Euplectella, commonly known as the “venus flower basket.” They 
lived in greatest abundance during later Devonian and early Carbon- 
iferous time, though their most ancient representatives occur far back 
in the Silurian. Their fossil remains are especially abundant in the 
sandstones of the Chemung formation in western New York, several 
extensive colonies of them having been discovered as they grew upon 
the ancient sea bottom. Notable collections of them have also been 
made in the Waverly sandstones in Ohio, and in the Keokuk shale at 
Crawfordsville, Ind., and from the last locality only, have specimens 
been found in which the spicular skeleton of the sponge has been pre- 
served. 
The variety of forms assumed by these interesting sponges is won- 
derful, and the earlier observers were at a loss to know where to place 
them in the zodlogical classification. Before their sponge nature had 
been definitely established by Whitfield in 1881, they had been 
described as cephalopods and as marine plants. In life these organisms 
must have been most beautiful objects, “with their manifold variety of 
