87 



all the numerous dangerous reefs between Table Cape and 

 Emu Bay. 



I am of opinion tliat this is the same conglomerate ■wbich 

 crops out ou the Dial lianqc, and whicli is assigned by Mr. 

 Gould to Siluriau age. It is composed of highly altered 

 water-worn pebbles derived from various ancient rocks. Some 

 of them are derived from a dark crystalline limestone, whicli 

 appears to be non-fossiliferous. 



One remarkable block, however, was, so far as I could learn, 

 picked out of this conglomerate by Mr. James Smith, of West- 

 wood, Forth. It is highly fossiliferous, the prevailing form, 

 as shown in various sections, is undoubtedly a species of 

 Brachiopod. I have not sufficiently studied this rock. I 

 have observed, however, that it has been greatly subjected to 

 denudation, and that it rests, so far as I could see, uncon- 

 formably upon a more or less inclined slate rock. 



GENERAL. 



I have thus referred as briefly as possible to the vertical 

 distribution of the organisms contained in the tertiary marine 

 beds at Table Cape. It is of the utmost importance, prior to 

 establishing any relations with similar isolated deposits else- 

 where iu Tasmania, Flinders Island, or the continent of Aus- 

 tralia* that each isolated bed or series of beds should be fully 

 investigated, especially as regards the extent and distribution 

 of its organic contents. 



While I do not deny that reasonable inference or conjecture, 

 so long as it is recognised as provisional, is most useful in 

 stimulating enquiry and helps to make interesting what would 

 otherwise be a chaos of isolated observations, yet as the ten- 

 dency to create minor subdivisions with reference to distant 

 European beds, is in many instances too apparent, it may be 

 the means of introducing mvich error into our classification. 



Among recent geological authorities of eminence, perhaps, 

 no one has drawn more particular attention to this source of 

 error than the late respected Mr. Jukes. 



In connection with chronological observation he thus writes 

 (p. 409, manual). " In order to avoid error each great dis- 

 trict of the earth, such as Europe or North America should be 

 surveyed separately, without reference to anything out of the 

 district, and that the order of superposition of its strata and 

 their classification into groups or formations, should be settled 

 independently on evidence to be found in the district only. 

 When this has been done the two series may be compared, and 

 the synchronism of difFerent parts of each may be decided ou," 



If such care be necessary in the determination of the great 

 • See table. 



