Geology and Mineralogy. 471 
Natural History, vol. ili, No. ix, (March, 1884), on new species of 
Cockroaches of the genus Mylacris, and on Myriapods of the 
7 
Morri and 
Pennsylvania and smite e praia In view of the ehereay of 
boniferous Myriapods was as great as among existing species. 
No trace of Myriapods has been found in this country below the 
Carboniferous; but they are known from the Old Red Rude a 
of Scotland. 
13. Macfarlane’s Geological Railway Guide—James Mac- 
ARLANE, T ; as commenced revising his American 
Geological Railway Guide for a second edition. He would be 
glad if persons who have used the book and made notes of correc- 
tions and additions, waar end them to him; or if it will bea 
ume) has at ear been removed b The results bd 
his analytical work, poate publishéd, coutirm those first giv 
by Mackintosh and go to show that ukler’s are entirely un- 
trustworthy. Four analyses were she by me Genth upon 
quantities of the mineral, respectively, 1°033, 0°8608, 0°3303, 
0°5860 grams, and the resu ults are iy en below, Bale ‘x with the 
analyses by Mackintosh and Winkle 
Ehren- 
Stoneham. friedersdorf. 
I I Ill IV Mackintosh. Winkler. | Winkler. 
P.0; = 41°76 43°01 43°38 43°43 443 A151 2°44 
BeO = 14°60 1501 15°17 15°04 15°76 14°84 8°61 
AT,O,; = O17 0°22 0-09 0-20 ets 2 6°58 
Fe,0; = 0°48 0°31 0°49 0°15 soe 118 1-77 
MnO = 0-09 0-08 0°12 0-11 Pa ss a 
CaO == 33°96 34-06 33-74 33°65 33°21 33°67 34-06 
BO ae os ae 20°61 20°61 a 
Fl Site 26-04 pier 8°9. 11°32 es ps 
10212 104°06 
Less O = 3°76 4°76 
98°36 99°84 
Dr. Genth gives in detail the method of analysis followed by 
him, and in conclusion says: 
“The analysis made by Mr. Mackintosh and myself show sl 
AM, panty ss Series, Vou. XXVIL, No, 168.—Dec., 1884. 
30 
