Tebeuaby 24, 1911] 



SCIENCE 



313 



could have been synchronous, since there is no 

 evidence of intermingling of species characterizing 

 the respective formations in the median areas of 

 interfingering overlaps. 



It is only the pelagic and semi-pelagic types 

 that can be depended upon for exact correlation 

 between widely separated areas, and prove the 

 existence of unobstructed current-highways. Re- 

 ferring to such organisms, the distribution of the 

 Eopaleozoic graptolites offers very strong argu- 

 ments against the hypothesis of transcontinental 

 currents in the interior basins. The most impor- 

 tant of the graptolite faunas are confined to cur- 

 rent-swept submarginal channels. Had these cur- 

 rente continued across the continental border, as 

 assumed by Willis, the graptolites must have been 

 carried by them into and through the interior 

 seas, a condition wholly negatived by the evidence 

 in hand. 



Perhaps the strongest argument against the 

 efficiency of currents in preventing deposition in 

 the interior continental seas is found in strati- 

 graphic overlaps. In any period of sea-advance, 

 beds are deposited by overlap toward the " posi- 

 tive " or relatively elevated areas. At the same 

 time, the submergence increasingly favors the 

 formation of currents. If currents were pre-eut 

 and competent to cause scour, phenomena quite 

 opposed to those observed would obtain. The 

 lower beds, which are absent, should be present, 

 and the later beds, formed in a sea supposedly 

 favorable to the extensive development of strong 

 currents, should not be deposited, or should show 

 the effects of current action by diminished 

 thickness. 

 Notes on Argentina: Bailey Willis. 



No abstract. Edson S. Bastin, 



Secretary 



THE 6E0L00ICAL SOCIETY OP WASHINGTON 



At the 235th meeting of the society, held on 

 December 14, 1910, Mr. M. R. Campbell, the 

 retiring president, presented an address, entitled 

 " Historical Review of Theories Advanced by 

 American Geologists Regarding the Origin and 

 Accumulation of Oil." 



At the close of Mr. Campbell's address the 

 eighteenth annual meeting of the society was held 

 for the purpose of electing officers, and the follow- 

 ing officers were elected for the ensuing year: 

 ' President — Mr. Alfred H. Brooks. 



Vice-presidents — T. W. Stanton and David 

 White. 



Treasurer — ^Hoyt S. Gale. 



Secretaries — Edson S. Bastin and Robert An- 

 derson. 



Members at Large of the Oounoil — W. C. Men- 

 denhall, Wm. C. Alden, F. C. Schrader, F. B. 

 Van Horn, Adolph Knopf. 



FEANgois E. Matthes, 



THE GEOLOGICAL SOCIETY OF WASHINGTON 



The 236th meeting of the society, held on 

 Wednesday evening, December 21, 1910, in the 

 Cosmos Club, was devoted entirely to a discussion 

 of Mr. E. 0. Ulrich's paper entitled "The Influ- 

 ence of Marine Currents on Deposition in Conti- 

 nental Seas," delivered before the society on No- 

 vember 30, 1910. 



The discussion was opened by Mr. Bailey Willis, 

 who summed up the propositions from which he 

 wished to dissent as follows: (1) that the epi- 

 continental seas of eastern North America during 

 the Middle Ordovician age were so landlocked 

 that marine currents could not have passed 

 through them with sufficient force to have influ- 

 enced the deposition of sediments, and could not 

 have kept the bottom clean of sediment in any 

 portion of the area which was submerged; (2) 

 that the Gulf Stream does not go to the bottom 

 of its channel and does not scour the bottom. 

 The first, which was brought forward by Mr. 

 Ulrich, he considered largely theoretical, and 

 founded upon an interpretation of the distribution 

 idea which has not sufiicient support in the phys- 

 ical evidence of unconformities that must have 

 been developed by subaerial decay and erosion 

 upon exposed portions. 



Mr. Willis recognized that there are areas 

 characteristic of the shores of the Ordovician sea 

 and of the shores of islands in that sea where 

 unconformities may be recognized by the usual 

 evidences of erosion; and also that there are other 

 localities where limestones are wanting that are 

 elsewhere developed to notable thicknesses. In 

 many of these partial sequences there is no evi- 

 dence of exposure to subaerial agencies. In these 

 eases it is reasonable to consider the alternative 

 proposition of marine scour as of at least equal 

 value in interpretation with that of the former 

 existence of land. 



In answer to Mr. Ulrich's statement that the 

 Ordovician seas were landlocked, he pointed out 

 the evidence brought forward by paleontologists 

 for the wide distribution of faunas composed of 

 numerous species, and maintained that marine 

 currents were the most effective agencies in pro- 

 moting that distribution. Were the seas so land- 



