244 PROCEEDINGS OP THE AMERICAN ACADEMY 



rock." All Orthoceratites found in the Taconic belong to the crenera 

 Siiiinionites, Piloceras, and true Ortlioccras. Finally, the Lituitcs of 

 Phillipsburgh are very rare in America, and disappear almost totally 

 with the " Taconic System." 



VI. Taconic versus Cambrian and Silurian. 



The time has now come to make clear the prior right and the real 

 advantage to be found in the use of the term "Taconic System," in- 

 stead of the so generally employed expressions " Cambrian " and " Si- 

 lurian," to designate the strata enclosing the primordial fauna. First, 

 it is a question of justice ; and it is hardly possible tliat the third In- 

 ternational Geologic Congress, which is to meet at Berlin, should fail 

 to consider the names to be chosen for the great divisions of formations 

 on the geological map of Europe. 



Facts and dates v^ill prove that America has the right to name one 

 of the great systems, or series of strata, and that the observations made 

 and work done on this side of the Atlantic have first made known the 

 true base of the stratigraphic scale. 



Murchison, not wishing to use the German name of " Grauwacke," 

 nor the French term " Terrain de transition," explains as follows the 

 origin of the terms Silurian and Cambrian.* 



"At this time [1835] I proposed the term Siho'ian, and it came 

 about in this way. IMy friend, the eminent French geologist, Elie de 

 Beaumont, seeing what a clear classification I had made out by order 

 of superposition and characteristic fossils in each descending formation, 

 earnestly urged me to adopt a name for the whole of the natural 

 groups. Seeing that the reg'ion in which the best tj'pes of it occurred 

 was really the country of the Silures of the old British king Caracta- 

 cus, I adopted that name [Silurian]. I had seen that all geological 

 names founded on mineral or fossiliferous characters had failed to sat- 

 isfy, and that fanciful Greek names were still worse. Hence it seemi d 

 to me that a well-sounding geographical term, taken from the very 



* Cambria, from the Latin Cimbri (robbers), and from tlie Celtic Crjmry, tlie 

 Britannia secunda of the Romans, comprehended the whole of Wales from 

 the river Severn to the river Dee. Three tribes inhabited it: on the south, the 

 Silures {Siluria) ; on the west, the Diinetes {Dimctia) ; and on tlie north, the Or- 

 dovices {Ordovicia). All these names have been used by Enplisli geologists, 

 who have also proposed other Welsh names, such as Menevian, I'ebidian, Ar- 

 vonian, Longinyrul, Llamberris, Ilarleck, Festiniog, Tremadoo, Arenig, Cara- 

 doc, etc. The little principality of Wales has furnished more geographical 

 names to geology than any other country. 



