Geology and Natural History. 75 



bundles, the prisms having the composition of the main mass of 

 crystals. 



In the second case the small variant crystallized toward the end 

 of the crystallization and contained more albite molecules than 

 the main mass of feldspar crystals. It had the same habit as the 

 other more calcic portion, and appears to have crystallized at the 

 same time with it, the crystals with different optical properties 

 being by the side of one another and not in zonal relation. 

 Neither of the feldspars represents the end members of the series, 

 An or Ab." 



The Introduction to the volume by Becker, to whom the orig- 

 inal plan of the work is largely due, will be read with much 

 interest. 



5. The Tin Deposits of the Carolinas ; by J. H. Pratt and 

 D. B. Sterrett. 64 pp. Raleigh, 1904. Bulletin No. 19 of the 

 North Carolina Geol. Survey, J. A. Holmes, State Geologist. — 

 The occurrence of tin in the country, and the southern states 

 particularly, is mentioned in Bulletin No. 260 of the Geological 

 Survey, noticed on page 70. This paper, by Pratt and Sterrett, 

 appears from the North Carolina Geological Survey and takes up 

 in detail the tin deposits of North and South Carolina. The first 

 discovery of tin ore was made near Kings Mountain, North Caro- 

 lina, in 1883, though but little progress was made uutil 1903, 

 when the Ross mine at Gaffney, South Carolina, was discovered. 

 During these twenty years, considerable prospecting has been 

 done on the Carolina tin belt, so that this can now be traced 

 quite definitely in a northeasterly direction from Gaffney, Chero- 

 kee county, South Carolina, across Gaston and Lincoln counties, 

 North Carolina. Tin deposits also occur in Rockbridge county, 

 Virginia. 



A full account is given of the work which has been accom- 

 plished thus far, and a brief statement is added of the occurrence 

 of tin in other parts of the country and abroad. At present, the 

 practical work in the Carolina belt is limited to hydraulic mining 

 in the alluvial gravels, the vein tin requiring different and more 

 expensive treatment. Such deposits as those of the Ross mine 

 are regarded as thoroughly remunerative, but in a large propor- 

 tion of the alluvial deposits the yield of cassiterite is relatively 

 small and this fact makes successful mining more problematical. 



6. Tubicolous Annelids of the Tribes Sabellides and Serpu- 

 lides from the Pacific Ocean ; by Katharine J. Bush, Ph.D. 

 8vo, 130 pp., 44 plates. — This admirable memoir forms part of 

 volume xii of the reports of the Harriman Alaska Expedition. It 

 includes a list of all known Pacific Ocean species of these groups 

 and a very complete bibliography. The systematic portion 

 includes full descriptions and illustrations of all the known 

 species from California to Alaska. In the case of Spirorbis all 

 the known species are reviewed from other regions also. Many 

 of the illustrations are from photographs reproduced as helio- 

 types. The northwest coast of America seems to be one of the 



