756 



SCIENCE. 



[N.S. Vol. XXII. No. 571. 



has extended the known limits of the Co- 

 manche series with its marine fossils to the 

 northwest corner of Oklahoma and into north- 

 eastern Colorado, and it has also proved the 

 extension of the Morrison formation into the 

 same area. These geologists believed that 

 they had traced the Morrison formation lat- 

 erally into the marine beds of the Comanche 

 series and that they had thus proved it to be 

 of the same age. 



During the past summer the area in ques- 

 tion was examined by Messrs. Lee, Stanton and 

 Gilmore and it was found that the beds con- 

 taining the Comanche fauna overlie the Mor- 

 rison formation wherever both horizons occur 

 in, the same section. This relation was seen 

 on Purgatoire River south of La Junta, Colo- 

 rado; on the Cimarron from Garrett, Okla- 

 homa, to the neighborhood of Folsom, New 

 Mexico ; on the Canadian north of Tucumcari, 

 JSTew Mexico ; and finally in Garden Park, near 

 Canyon City, Colorado, at the noted locality 

 for Morrison vertebrates. At all these locali- 

 ties the Comanche horizon has previously been 

 included among the beds referred to the Da- 

 kota, and the error in coTrelation when the 

 Comanche fossils were supposed to have come 

 from beds of Morrison age was due to the 

 failure to locate the fossils accurately in the 

 local sections. The Morrison formation un- 

 derlies all the Comanche beds that extend into 

 the same area, and is, therefore, distinctly 

 older than those with which it was supposed 

 to be contemporaneous. The question whether 

 it is Upper Jurassic or Lower Cretaceous is 

 still left open. The Dakota formation is 

 much more intimately connected with the Co- 

 manche series than is the Morrison. 



The Buhdivisions of the Shenandoah Lime- 

 stone: Mr. R. S. Bassler. 

 The name Shenandoah limestone proposed 

 by Darton for the Valley limestone of early 

 geologists was made to include all the lime- 

 stones in the Valley of Virginia occupying 

 the interval between the Cambrian quartzites 

 and the Upper Ordovician shales. The lower 

 portion of the great limestone series had been 

 found by Mr. Walcott to include Lower, 

 Middle and Upper Cambrian rocks, but the 



Oi'dovician portion had been determined only 

 to the extent that Trenton strata were sup- 

 posed to occur at the top. The work of the 

 writer in Virginia brought out the fact that 

 the geologic succession of the Ordovician divi- 

 sion was quite different in various parts of the 

 Valley. In northwestern Virginia a great 

 thickness of Beekmantown is overlaid by 1,000 

 feet of Stones River, and this in turn by 400 

 feet of Black River, while the strata-bearing 

 Trenton fossils form the lowest division of the 

 overlying shales. In central western Virginia 

 the Black River alone rests upon the Beek- 

 mantown, but in southwestern Virginia two 

 distinct arrangements were noted. Along the 

 western edge of the Valley the Beekmantown 

 is followed by 1,000 or more feet of Stones 

 River but no Black River, while along the 

 eastern side only the Black River occupies the 

 interval between the overlying shales and the 

 Beekmantown. In each case the Trenton does 

 not form the upper part of the limestone, but 

 is the basal member of the overlying shales. 

 The Shenandoah limestone, therefore, is a 

 broad term, embracing strata of Cambrian and 

 Ordovician age, the geologic succession of the 

 latter varying in different parts of even the 

 *yP^ ^^ea. ;^_ -^ Puller, 



Secretary pro tern. 



THE NATIONAL GEOGRAPHIC SOCIETY. 



The National Geographic Society, whose 

 headquarters are in Washington, will conclude 

 the eighteenth year of its history on December 

 31 of this year. The society has a member- 

 ship of considerably over 10,000, which makes 

 it the largest geographical association in the 

 world. About 1,400 of its members reside in 

 Washington, while the others are well dis- 

 tributed throughout the United States and in 

 foreign countries. The annual dinner of the 

 society will be held at the ISTew Willard in 

 Washington, D. C, on December 20. The 

 Secretary of War, Hon. William H. Taft, and 

 Mrs. Taft will be the guests of honor of the 

 society. The following program of meetings 

 for 1905 and. 1906 has been arranged for 

 Washington. The majority of the addresses 

 are published in the magazine of the society. 



