1862.] HODGSON UL VERSION - . 29 



as I can prove ; for in workings which have been abandoned, the 

 small particles of ore, which exist throughout the whole of the district, 

 have, by the action of the water, been washed through the cavities 

 in the limestone, and been deposited in quantities sufficiently large 

 to be worked." 



Diatornacece and Plants. — At the risk of some recapitulation, I 

 must not omit acknowledging that the idea of the clay having been 

 very lately deposited did not entirely originate with myself. The 

 opinion of one or two eminent microscopists, that the species of 

 Diatomacem might confidently be expected to occur in its neighbour- 

 hood in a living state, served to suggest the possibility of its having 

 been in some way conveyed below ground ; whilst the remarks of 

 equally eminent botanists, who detected for me the presence of 

 rushes and other familiar water-side plants, further tended to 

 strengthen the idea, and to impose the necessity of discovering its 

 impracticability, before yielding to the deposit that antiquity which 

 its position would appear to claim for it. 



After ascertaining with accuracy the species of Diatomaceaz con- 

 tained in the deposit, and noting to what conditions of growth they 

 might be referred, it was found that not only did they belong to a 

 peaty and subalpine district, but also to running streams (the 

 peculiar habitat, if I do not mistake, of the species of freshwater 

 sponge found in the deposit) ; all clearly indicating the hills and 

 moors north of Lindale, and the streams and peat-bogs which occur 

 there, as their source ; and thus, without any previous knowledge of 

 the district, its interesting features, as I have detailed them, became 

 successively disclosed, and seemed to invite close and persevering 

 investigation. 



All the waters on Lindale Moor that could find access to the 

 Swallow-holes were examined, and also the dry soils in the vicinity. 

 All yielded Diatoms, including a few of the deposit-species, just 

 sufficient perhaps to prove the correctness of altitude, but failing in 

 some, from the absence of peaty or boggy ground ; a result at once 

 acting as an unerring guide to the district further west, towards the 

 channel of the Poaka Beck, where the interesting facts connected 

 with that stream soon after developed themselves, and tended indu- 

 bitably to confirm, in all points, the preconceived idea. 



Much of the arable and pasture land on the sides of the Beck, near 

 Stewnor Park, was, thirty or forty years back, nothing but peat-bog. 



With a view of obtaining the Diatomaceaz which might have lived 

 upon the surface at that time, samples of bog were taken up by means 

 of an iron rod from the depths of 2, 4, and 5 feet, on different parts 

 near the Beck-course. 



The following tabular list of the Diatoms found in the deposit will 

 at one view show its character, and also with what success the repre- 

 sentatives of the Diatoms have been searched for in the Poaka Beck. 

 Allowing for the lapse of years, and the great changes that have been 

 effected in what may be called the principal Diatom -ground on the 

 course, the few species yet undiscovered ought not to negative the 

 belief that the deposit has been supplied from thence ; for there can be 



