Geology and Mineralogy. 73 



tures of the Atlantic and Pacific are treated of at length, with 

 the consideration of the causes for these differences. The ex- 

 tended reading of Professor Suess has given him a large fund of 

 facts to add to his own extended observations, for use in these 

 discussions, and his method is so comprehensive and his style so 

 attractive, that such a book as the present is at once to a high 

 degree interesting and instructive. 



9. Chert. — Dr. G. J. Hinde has examined microscopically 

 chert from the Permo-Carboniferous strata of Spitzbergen, and 

 has proved that the material consists in many parts of closely- 

 packed sponge spicules, passing often into a nearly pure trans- 

 lucent chert. The bed at Tempelberg was about three feet thick 

 and contains also " casts of Product us and possibly also of Spiri- 

 fer." He figures the spicules from specimens of different locali- 

 ties, and pronounces the chert of organic origin. A siliceous 

 schist associated with the chert, was largely made of siliceous 

 sand but contained many sponge spicules. On Axel's Island the 

 cherty beds are 870 feet thick; and in view of all the facts he 

 has observed since he commenced his investigations of chert, he 

 thinks it not extravagant to conclude that although so thick the 

 whole is " due to the accumulation of the skeletal debris of sili- 

 ceous sponges." — Geol. Mag., June, 1888, p. 241. 



10. Dumortierite from a new locality. — MM. Michel Levt and 

 Lacroix announce the discovery of the rare aluminum silicate, 

 dumortierite, in the iolite of the gneiss of Tvedestrand, Norway, 

 where it is associated with sillimanite. It is distinguished, as in 

 other cases, by its pleochroism. — C. H., cvi, 1546, May, 1888. 



11. Zircon from Xorth Carolina. — The recent demand for zir- 

 conium, for use in the arts, lias led to a systematic effort to mine 

 it in large quantities. Once regarded as a rare mineral, it has 

 been found possible to obtain within six months twenty-five tons 

 from the Green River mines, Henderson Co., North Carolina; 

 the mining has been carried on under the charge of Mr. W. E. 

 Hidden, who gives this information. It is also anticipated that 

 the attempt soon to be made to obtain monazite in similar large 

 quantities will be successful. 



12. Seventh Annual Report of the State Mineralogist of Cali- 

 fornia for the year ending Oct. 1, 18S7; by William Irelax, 

 Jr. 315 pp., 8vo. Sacramento, 1888. — This report is devoted to 

 the subjects of petroleum, asphalts, natural gas, coals and build- 

 ing stones, and gives much valuable information as to their oc- 

 currence, method of working, use and so on. Much of the matter 

 is contributed by W. A. Goodyear and A. H. Weber, field assist- 

 ants to the State Mineralogist. The report closes with a cata- 

 logue of the Californian fossils, compiled by Dr. J. G. Cooper. 



13. Contributions to the Mineralogy of the Pacific Coast; by 

 W. Lixdgrex. — A description is given of a chromiferous chlorite 

 related to kotschubeite, obtained from Green Valley, on the 

 American River. It occurs in rosettes of thin hexagonal tables 

 having a peach-blossom red color, and also in fibrous massive 



