FOSSILS OF THE ACADIAN GROUP, 643 



Etages C. and D. in Bohemia ; but these terms, unless limited, should 

 not be extended to equivalent groups of the same age, but forming 

 distinct faunae, in other parts of the world, for such a double emploi is 

 incompatible with that precision which should mark the use of scientific 

 tenns. Primordial zone is objectionable. If the term Primordial is 

 used, and it is very appropriate, it would be much better to say 

 Primoi'dial period, — period, as used by Agassiz, being equivalent to 

 Jiarrande's Stage. 



" The lower part of the St John group, at Coldbrook, has been 

 divided by Mr Matthew, on lithological grounds, uito three bands, 

 viz. : — 



" No. 1. TheloAver or arenaceous band, with no detei-minable fossils, 

 and constituting passage beds from the Coldbrook group. 



" No. 2. Argillaceous shales, rich in fossils, Paradoxides^ Orthis, 

 Conocephalites, Obolella. 



"No. 3. Carbonaceous shales, full of fossils, Paradoxides, Conocepha- 

 lites, Orfhis, Discina, etc., all much distorted. 



" I have not observed No. 2, at Ratcliflfe's Millstream. No. 3, at 

 Coldbrook, corresponds exactly, in its fossil remains, to the bed at 

 the Millstream, from which the Trilobites, etc., were obtained. 

 Nearly, if not all the fossils I have seen from No. 2, at Coldbrook, are 

 entirely distinct from those of No. 3 of the same locality and the Mill- 

 stream ; but more material is required to establish the claim of these 

 two beds to be considered as being characterized by distinct succes- 

 sive fauuEe. At all events, all the species from both beds are different 

 from those elsewhere occurring, and for at least bed No. 3, we have 

 in the vicinity of St John a distinct fauna of the Primordial period." 



Other engagements have prevented Mr Haitt from fulfilling his 

 intention of publishing detailed descriptions of the species. In com- 

 pliance, however, with my desire to place these interesting forms 

 before geologists in this work, he has kindly communicated to me 

 his MS. notes ; and I have extracted fi'om these the following 

 descriptions of several of the more common species, with notices of 

 the others : * — 



Eocystites primaevus, Billings, Coll. Hartt (Fig. 220). Fig. 220. 

 The little plate with radiating sculpture, re^jresented 

 somewhat enlarged in the figure, is regarded by Mr 

 15illings, to whom the specimens have been submitted, 

 as indicating a new genus of Cystideans. Eocystites. 



* Mr Hartt desires me to state his obligations to Professor Agassiz for the oppor- 

 tunity of coin))ariiig these fossils with specimens in tiie Museum of Comparative 

 Zoology, (,'anibridge, U.S. 



