266 Scientific Intelligence. 



Vicksburg and Appalachicola groups. Three of the four forma- 

 tions of the latter are believed to have been deposited contem- 

 poraneously. Two formations have been distinguished in the 

 Miocene, live in the Pliocene, including the Lafayette. The 

 various formations are discussed in detail, pp. 50-162. The 

 Pleistocene geology is unusually interesting here because of 

 abundant proof of several elevations and depressions of the penin- 

 sula, including movements going on at the present time. Modi- 

 fied drainage, sea cliffs and terraces are topographic features 

 abundantly represented. 



The report of Samuel Sanford on the Topography and Geology 

 of Southern Florida (pp. 177-231) is the iyst attempt at a com- 

 plete geological description of this area. The studies include 

 the Everglades, the Coastal Plain, and the reefs and keys along 

 the line of the Florida East Coast Railway. Owing to the recent 

 deposition of the beds and their more recent elevation, the 

 topography of this area is in a stage of infancy. " Drainage is 

 defective, sloughs, shallow ponds and lakes abound. Most of the 

 interior is a swamp, there are no well-defined river systems nor 

 stream valleys, and some of the short rivers that flow from the 

 Everglades into the Atlantic are, where bed rock comes a few 

 feet above tide level, characterized by rapids in their upper 

 courses." The author agrees with Dall that " the present Florida 

 mainland is but the top of a vastly greater submarine plateau, 

 the southeastern and southern edges of which are near the pres- 

 ent shore line, the western edge many miles to the west." One 

 of the striking features of southern Florida is the absence of 

 rock outcrops over wide areas where the ledge is but a few feet 

 below the surface. Part of the extensive mantle of sand which 

 so effectually conceals the bed rock has been carried down the 

 Atlantic coast by waves and currents, and part of it comes from 

 the disintegration of arenaceous linestones and marls. 



The State Geologist discusses the origin, distribution and com- 

 mercial importance of phosphates, diatomaceous earth, fullers' 

 earth, and other economic products. h. e. g. 



2. Report of Topographic and Geologic Survey Commission 

 of Pennsylvania, 1906-1908. Pp. 375, 21 plates and 21 figures, 

 Harrisburg, 1908. — The First Geological Survey of Pennsylvania 

 under the direction of H. D. Rogers was organized in 1836, and 

 issued reports in 1836, 1838, 1840, 1841, and 1842, with two vol- 

 umes of final reports in 1858. The Second Geological Survey, 

 organized in 1874 under the direction of J. P. Lesley, was con- 

 tinuously in operation from 1874 to 1887, issuing 77 volumes, 38 

 atlases, in addition to a "grand atlas." Three volumes of the 

 final report of this survey were issued in 1893-1895. In 1899 a 

 topographic and geologic survey was organized to work in cooper- 

 ation with the United States Geological Survey. Under these 

 auspices work was carried on under the general direction of M. 

 R. Campbell until 1894, when the general supervision was placed 

 in the hands of George H. Ashley. The results of the work have 

 been published from time to time by the United States Geologi- 



