Review of Recent Geological Literature. 249 
REVIEW OF RECENT GEOLOGICAL 
LITERATURE. 
Die Silurischen Craniadgii der Ostseclander //lit aiissch/i/ss Got- 
lands. Von Friedrich Baron Hoyningen-Huene. (Verhandlung- 
en der Kaiserlichen Russischen Mineralogischen Gesellschaft zu St. 
Petersburg. Zweite Serie, Bd. XXXVl, No. 2.) 
Under the above title, Baron von Hoyningen-Huene has published a 
very good account of the Craniadas, an essay which for completeness 
and grasp of the subject is comparable to Michwitz book on the genus 
Obolus. 
Herr von Huene recognizes the following genera under Craniadse — 
Pseudocrania, McCoy, Pholidops, Hall, Pseudometoptoma, Huene, Eleu- 
therocrania, Huene, Philhedra, Kokm (emmend. Huene) and Craniella, 
Oehlert. 
The first section of the essay is taken up with an account of the animal 
and its shell; and a historical account of what has been written in refer- 
ence to the family under review. The second section contains a descrip- 
tion of the family, with keys to the genera and sub-genera; and the 
stratigraphical and geological distribution of the Baltic species. 
The genera and species of the Baltic provinces are thus described in 
full. 
The third section reviews and gives conclusions in reference to the 
Baltic Craniadas and a comparison of the forms of this family with other 
brachipods. 
Quite a number of cuts, showing the characters of the different genera 
are scattered through the text, and six large plates with figures of the 
Baltic species are given. One plate showing the relation of the muscle- 
scar in several genera of inarticulate brachiopods is very suggestive. 
One table (p. 268) in the text shows a regular procession of species of 
the genus Pholadops from the Lower Ordovician to the Carboniferous. 
Another at page 328 shows the distribution of the Craniadas in time and 
the several geological.systems in which the different genera are found 
to prevail. G. f. m. 
Nogra Anteckningar om Vestergotla/id Oftersiliiriska Gi-aptolit- 
skiffrar. Af Sv. Leonh. Tornquist (Geol. Foren i Stockholm Forhandl., 
Bd. 21, Hft. 7, iSqq.) 
Dr. Tornquist herein describes the species of graptolites found in the 
several zones of the Upper Silurian shales of the province of Vestergot- 
land and refers to the work of Linnarsson, Holm, Moberg, and others 
in connection with the Graptolites of this formation. g. f. m. 
A Preliminary Report o/i a Part of the Clays of Georgia. By 
George E. Ladd, Assistant Geologist. Bulletin No. 6-A, Geological 
Survey of Georgia; W. S. Yeates, State Geologist. Pages 204, with 17 
plates, a map, and 11 figures in the text; 1898. 
This volume describes the clay deposits and industries in the vicinity 
