428 Correspondence. 



the drift series. Tlie existence, however, of Mr. Harmer's " Third 

 Boulder-clay," as a distinct formation, seems to depend on the 

 certainty of the coast beds being inferior to those of High Suffolk. 

 The small patches of Boulder-clay in the Yare Valley are clearly 

 more recent than the drifts that have been cut through to form the 

 valley ; but does it not seem less improbable that the coast beds may 

 be identical with them, than that these isolated patches of a marine 

 deposit should have been the solitary result of the submergence during 

 which they were formed ? 



George Maw. 

 Benthall Hall, Broselet, 

 Atiffusi 6th, 1867. 



"THE LOB-WOEM EPOCH." 

 To the Editor of the Gteological Magazine. 



Sir, — Colonel Greenwood's remarks in the August number of the 

 Geological Magazine on the " Lob-Worm Epoch " tempt me to lay 

 before your readers a few facts concerning the rocks of that period, 

 as shown in this neighbourhood, and the results obtained by their 

 examination during the last few years. 



Mr. Salter and myself have for some time felt convinced that most, 

 if not the whole, of the Cambrian rocks belonged to a fossiliferous 

 period, and accordingly in our own report to the British Association 

 in 1865, on the " Lower Lingula-flags " (Menevian group) and its 

 fossils, it was stated that, " though the purple band series have not 

 yet yielded any definite traces of these higher forms of fossils, we 

 are scarcely warranted in looking upon that as a proof of their absence ; 

 neither is it likely that so rich, though limited, a fauna should come 

 so suddenly into existence." Since then I have been fortunate enough 

 to find fossils in these identical purple beds, which prove the facts at 

 that time only conjectured. 



In a paper by Mr. Salter and myself, read before the Geological 

 Society on June 19th, an account is given of the finding of a Lingu- 

 lella in the red rocks of the Lower Cambrian-rocks, hitherto deemed 

 quite destitute of higher organisms than worms, and belonging to the 

 very series mentioned by Mr. Baily. I have found also, subsequently 

 to the reading of the paper referred to, a whole colony of species 

 (trilobites, etc.) still lower down, showing, beyond a doubt, that 

 much, if not the whole, of the so-called "worm epoch" represents 

 a time when animals of much higher forms than worms were in 

 existence, and flourished in the seas of the period. I therefore feel 

 satisfied that if active explorations be carried on in North and South 

 Wales, it will he proved that the series throughout is truly fossiliferous, 

 but I am also sensible that some time will be required to decide 

 the fact, since the working of the strata is, in many ways, difficult, 

 and the deposit from its very nature, as a rule, imfavourable to the 

 exhibition of organic remains. 



Moreover we are sure to find, especially in so extensive a series, 

 much that is but very slightly fossiliferous, or, indeed, almost barren, 

 intervening between colonies of rich faunas. Such is really the case 



