288 THE CANADIAN NATURALIST. [Vol. vi. 



address, that researches in Germany, Belgium and Russia led to 

 the conclusion that the " fossiliferous strata characterized by Lower 

 Silurian Orthidaa are the oldest beds in which organic life has 

 been detected." [Proc. Geol. Soc. Ill, 641, et seq.] The Orthids 

 here referred to are, according to Salter, Ortliis caUigramma, 

 Dalm, and its varieties. [Mem. Geol. Survey III, part 2. 335- 

 337.] 



Meanwhile Sedgwick's views and position began to be misre- 

 presented. In 1842, Mr. Sharpe, after calling attention to the 

 fact that the fossils of the Bala limestone were, as Sedgwick 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 Murchison on Sedg- 

 wick's authority. [Proc. Geol. Soc. IV, 10.] This statement 

 Murchison suffered to pass uncorrected in a complimentary re- 

 view of Sharpe's paper in his next annual address (1843). In 

 his JSUuria, 1st edition, page 25, (1854) he speaks of the term 

 Cambrian as applied (in 1835) by Sedgwick and himself " to a 

 vast succession of fossiliferous strata containing undescribed 

 fossils, the whole of which were supposed to rise up from beneath 

 well-known Silurian rocks. The Government geologists have 

 shown i\idiii\i\^ supposed order of superposition was erroneous," &c. 

 5^he 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 historical 

 sketch, which precedes, clearly shows the real position of Sedg- 

 wick in the matter, we may quote farther his own words : *' I 

 have often spoken of the great Upper Cambrian group of North 

 Wales as inferior to the Silurian system, * ^ * ^i^ ^i^ on the sole 

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

 times repeated explanations of them before they were published. 

 So great was my confidence in his work that I received it as per- 

 fectly established truth that his order of superposition was un- 

 assailable. ^ ^ ^ ^ 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 un- 

 varying 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. Mag. IV, 

 viii, 506.] That there must be a great mistake either in Sedg- 



