72 Scientific Intelligence. 



Ohio, with three plates, by Mr. Foeeste ; on the Geology and 

 Lithology of Michipicoten Bay, by C. L. Herrick, W. G. Tight, 

 and H. L. Jones; on the determination of the Horizontal Compo- 

 nent of the Earth's Magnetic force, by L. E. Akins, explaining 

 method of observation ; and a list of Alga? of the vicinity of 

 Granville, by H. L. Jokes. 



The paper on the Geology and Lithology of Michipicoten Bay 

 bears on the Hnronian question and is illustrated by three plates. 

 The rocks are granite, .which is described as eruptive ; the meta- 

 morphic schists, mica schist, chlorite schist, hornblende schist, 

 epidote schist, gneiss, etc., with dioryte and diabase ; and uncon- 

 formably over the schists there are the conglomerates and sand- 

 stones with intercalated and intrusive diabase of the Kewenaw 

 series, which, besides covering Michipicoten Island, occur on the 

 shore at Cape Cargatitia. The conglomerates consist of material 

 derived from the schists and other crystalline rocks. It is inferred 

 that a long interval elapsed between the era of the latter forma- 

 tion and that of the schist. 



8. A sketch of the Geological Development of the Pacific 

 Slope; by G. F. Becker. — This short but interesting paper is No. 

 5 of the Proceedings of the Natural History Society of Newport, 

 R. I. 



9. First Report on the Florida State Geological Survey, 1887 : 

 by J. Kost, M.D., LL.D., 32 pp. 8vo, 1887.' This first report 

 contains no results of new investigations. 



10. Brief notices of some recently described minerals. — Lang- 

 banite. Occurs in hexagonal crystals, varying in habit from 

 short prismatic to tabular ; the latter are quite complex and re- 

 sembles apatite somewhat, but differ from it in being holo- 

 hedral ; the vertical axis is 1 '64:37. The other physical charac- 

 ters are : hardness =6*5, specific gravity =4-918 ; luster metallic; 

 color iron-black; streak brown; fracture conchoidal. An analysis 

 yielded : 



Sb 2 O s Si0 2 MnO FeO 



15-42 10-88 64-00 10-32 = 100-62 



This the author interprets as a silicate of manganese (Mn 5 Si0 7 ) 

 with antimonate of iron (Fe 3 Sb 2 8 ) in the ratio 37:10. Lang- 

 banite occurs sparingly in granular limestone with schefferite, 

 magnetite and rhodonite at Langban in Sweden. Described by 

 G. Fliiik in Zeitschr. Fryst., xiii, 1, 1887. 



Webskyite. A decomposition-product of serpentine occurring 

 in crevices in the paleopikrite of Amelose, near Biedenkopf, in 

 Nassau. It has a black color in the mass, but green or greenish 

 brown in thin splinters; specific gravity 1*77 1. The mean of 

 two analyses gave : 



Si0 2 AloOs, Fe 2 3 FeO MgO H,0 H 2 



' , (below 110°) 



34-91 9-60 3-13 21-62 9"84 21-20=100-30 



Named after the late Professor Websky, of Berlin, by R. 

 Brauns, Jahrb. Min., Beilageband v, 318, 1887. 



