Palaeozoic Geology. 555 



Now the first question is, have any such new lights been thrown 

 upon the subject of the older rocks by the recent work of Mr. 

 Pliillips upon Devonshire, as to change the nomenclature previously 

 adopted both at home and abroad, and to substitute for it that pro- 

 posed by Mr. Phillips, namely, Upper, Middle, and Lower Palaeozoic 

 strata ? I confess that as I read this volume I perceived none, ex- 

 cept that after describing the species, the author shows that the fos- 

 siliferous strata of the Eifel are the equivalents of those of South 

 Devon, a point, however, which had been previously established by 

 Professor Sedgwick and myself. 



Adopting from ourselves the word " Palffiozoic," Mr. Phillips ex- 

 tends however its original meaning, and applies it to all the strata con- 

 taining organic remains, from the oldest formation to the Magnesian 

 limestone inclusive. His Lower Palaeozoic rocks ai-e admitted to be 

 exactly synchronous with those which were worked out aa types 

 under'the name of Silurian, and yet he entirely omits that term in his 

 parallel table of equivalents, in which he styles them " Transition 

 and Primary Strata;" whilst for the ordinary names to parallel with 

 his " Middle Palaeozoics," the much newer terms of Eifel and South 

 Devon are made use of — terms of comparison, it will be recollected, 

 which were introduced by Professor Sedgwick and myself long after 

 the establishment of the Silurian type. I ask those geologists who 

 supported me by their approbation throughout my labours, if the 

 name first proposed by him who worked out and defined a system 

 of classification, is to be suppressed when not only no evidence is 

 brought to disprove its value, but when succeeding observers in 

 various parts of Europe and America have sanctioned it. But as 

 this is now simply a subject of nomenclature, and ray facts are not 

 disputed, let us see whether for all the practical purposes of our 

 science, the term Silurian, as first proposed, ought to be preferred, 

 in use, to the term " Lower Paleozoic," which is to supplant it. 

 The word was chosen because it was liable to no misconceptions, 

 and never could lead to false theoretical deductions. It is, as be- 

 fore stated, simply a geographical name, derived from a region con- 

 taining newly defined types of succession. "When subsequently we 

 used "Palaeozoic" as a comprehensive term for all the older rocks. 

 Professor Sedgwick and myself intended to apply it generally to 

 that great series which embraces the Carboniferous, Devonian or 

 Old lied Silurian and Cambrian groups. 



In extending the palaeozoic range so as to include the magnesian 

 limestone, Mr. Phillips does so because that formation contains some 

 species of Product! very analogous to carboniferous forms. But he 

 knows well that rocks of the same age in Germany and in our own 

 country, contain the re mains (^' several species of Saurians, and the 

 recent exploration of Russia (1841 ) further establishes the important 

 fact, that dc])u9its in the very same place in the series as the magne- 

 sian lim(!»tone, and loaded with Product!, are also charged with Sau- 

 rians. What, then, are the zoological bases which ought to define the 

 boundary lines l)etween large groups of strata ? Are thoy the verte- 

 brata or invcrtebrata ? If such a great feature of change in animal 

 2 P2 



