REVIEWS 209 



best stone in the quarries is interstratified with beds of unsalable mate- 

 rial, which naturally interfere with the economy of working. 



Slate has been quarried in two different areas in Maryland, known 

 as the Peach Bottom district and Ijamsville. The former district is 

 the only one in which quarrying is now actively carried on. From 

 this district a good quality of slate is obtained. The output has shown 

 a slight decrease since 1894, when it reached its maximum importance. 



E. R. Buckley. 



Fifteenth Afmual Report of the State Geologist [New York) for the 

 Year 1893, Vol. I. James Hall, State Geologist, Albany, 

 1898. 



This report, published in a ponderous volume of 738 pages with 

 broad margins, large type and heavy paper, is particularly unwieldy, 

 and would be far more convenient for the student were it issued in a 

 size and form conformable with the preceding reports of the survey. 

 It is particularly aggravating to the librarian to have a continuous 

 series of reports which should be kept together upon his shelves vary 

 so greatly in size. The 1894 report and those preceding it are con- 

 venient sized octavo volumes, while this 1895 report is a great book 

 standing fourteen inches high, although the matter contained, page 

 for page, is about equivalent to that in the earlier reports. The edi- 

 tion of the report, issued as a part of the regents' report of the New 

 York State Museum, is printed upon thinner paper, and has the mar- 

 gins trimmed down so that it is a more convenient size, but even that 

 is considerably larger than the preceding reports of the survey. 



The criticism upon the style of publication, however, cannot be 

 extended to the contents of the volume as each one of the papers 

 communicated is a valuable addition to the literature of New York 

 geology, and many of them are of more than local interest. Each 

 of the papers will be briefly noticed, much of what follows being 

 taken from the "Synopsis of Results" by the state geologist upon 

 pages 11-26 of the report. 



Two paleontologic papers, both by James Hall, (1) "A Discussion 

 of Streptelasma and Allied Genera of Rugosa Corals," and (2) "The 

 Paleozoic Hexactinellid Sponges Constituting the Family Dictyo- 

 spongidae," are announced in the synopsis of the report but do not 

 appear. However, since this volume is marked Volume I on the title- 



