358 CAMBRIAN AND SILURIAN IN EUROPE. [XV. 



had long before shown, identical with those of Murchison's 

 Lower Silurian, declared that Sedgwick had placed the Upper 

 Cambrian, in which the Bala beds were included, beneath the 

 Silurian, and that this determination had been adopted by Mur- 

 chison on Sedgwick's authority. (Proc. Geol. Soc., IV. 10.) 

 This statement Murchison suffered to pass unconnected in a 

 complimentary review of Sharpe's paper in his next annual 

 address (1843). Subsequently, in his Siluria, first edition, 

 page 25 (1854), he spoke of the term Cambrian as applied (in 

 1835) by Sedgwick and himself "to a vast succession of fossil- 

 iferous strata containing undescribed fossils, the whole of which 

 were supposed to rise up from beneath well-known Silurian 

 rocks. The government geologists have shown that this 

 supposed order of superposition was erroneous," etc. The 

 italics are the author's. Such language, coupled with Mr. 

 Sharpe's assertion noticed above, helped to fix upon Sedgwick 

 the responsibility of Murchison's error. Although the histori- 

 cal sketch, which precedes, clearly shows the real position of 

 Sedgwick in the matter, we may quote further his own words : 

 " I have often spoken of the great Upper Cambrian group of 

 ^North Wales as inferior to the Silurian system, .... on the 

 sole authority of the Lower Silurian sections, and the author's 

 many times repeated explanations of them before they were pub- 

 lished. So great was my confidence in his work, that I received 

 it as perfectly established truth that his order of superposition 



was unassailable I asserted again and again that the Bala 



limestone was near the base of the so-called Upper Cambrian 

 group. Murchison asserted and illustrated by sections the 

 unvarying fact that his Llandeilo flag was superior to the 

 Upper Cambrian group. There was no difference between us, 

 until his Llandeilo sections were proved to be wrong." (Philos. 

 (4), VIII. 506.) That there must be a great mistake 

 either in Sedgwick's or in Murchison's sections was evident, 

 and the government surveyors, while sustaining the correctness 

 "f thse of Sedgwick, have shown the sections of Murchison to 



been completely erroneous. 

 The first step towards an exposure of the errors of the Silu- 



