Geology and Natural History. 487 



and important contributions to the science. After a review of the 

 work in progress through the year, there are Reports on the 

 Hawaiian Volcanoes, by Captain C. E. Duttojsj (pp. 81-212); ab- 

 stract of a Report on the Mining Geology of the Eureka District, 

 Nevada, by Joseph S. Curtis (pp. 225-251) ; Popular fallacies re- 

 garding the precious metal ore deposits, by Albert Williams, Jr. 

 (pp. 253-271) ; A Review of the fossil Ostreiclae of North America, 

 by Dr. C. A. White (pp. 281-316) ; a sketch of the Life History 

 of the Oyster, by J. A. Ryder (pp. 315-334); A Geological 

 reconnaissance in Southern Oregon, by Israel C. Russell (pp. 

 438-464). Captain Dutton's report is an elaborate memoir on the 

 Geology of the Hawaiian Islands, and a very valuable contribution 

 to the subject of volcanoes, prepared after a careful study of the 

 region. To give any adequate abstract of the memoir would 

 require the space of an article. All the reports are well illustrated 

 by maps, sections, cuts, or plates. 



2. Geological Sketches of the Precious Metal deposits of the 

 Western United States, by S. F. Emmons and G. F. Becker. 

 With notes on Lead Smelting at Leadville. 296 pp. 4to. From 

 the 10th IT. S. Census Report, vol. xiii. Washington, 1885. — 

 This report is a popular, but not less a scientific, account of the 

 great Western mining regions ; and it is well adapted to its 

 place in the Census report. It reviews the geological structure, 

 mining deposits and mines for each of the States and territories 

 in the west, giving sections of deposits, and tables mentioning 

 the rocks and minerals of the various mines. The geologist and 

 those interested in mines and the associations of ores, and in the 

 sources of mining wealth in the country will find the report full 

 of interest. The authors know well their subject, and describe 

 the regions largely from personal study. 



3. Malesia : Plantoz Ospitatrici. — In a former number (p. 245) 

 we gave an abstract of Beccari's investigations and illustrations 

 of those singular plants which, by an organic change of structure 

 supply food and lodging to certain species of ants. The third 

 part of the second volume of Malesia has now come to hand. It 

 is wholly occupied with this subject, and illustrates it by 29 more 

 plates of Myrmecodia and Hydnophytum, several of them show- 

 ing the formicaries. Thirty species of Hydnophytum are here 

 characterized, along with two more species of Myrmecodia. A 

 general review is made of this group of Pubiacece, of the struc- 

 ture of the tubers, the formation of the galleries, their internal 

 conformation, and of the ants that live in them, thus completing 

 a monograph of the subject so far as these hospitable Rubiacem 

 are concerned. a. g. 



4. Illustrationes Plorce Atlanticm. — The Flora of the French 

 possessions in Northern Africa is making good progress, at least 

 in the illustrations. The energetic Dr. Cosson brought out the 

 first fasciculus of these fine imperial quarto plates, with their 

 letter-press, in 1882. We have now received the second fascicu- 

 lus, with the date of 1884. The plates (tab. 26 to 50) are all of 



