walcott.J SUMMARY NEW BRUNSWICK. 265 





Thickness 

 in feet. 



2 {a) Purplish red Conglomerate, more friable than 1 a 35 



(6) Soft purplish red shales, with green glauconite grains, the upper part 



firmer and more sandy, greenish gray layers interspersed especially 



towards the base. Platysolenites, Obolus, Volborthella, etc 175 



(?) Purplish sandy shales, with a few bauds of greenish shale. Worm-casts 



(Scolites) , 300 



Measures concealed, probably of this series 320 



1,200 



x Iu this series of 1,000 or more feet of beds, the very oldest layers which are fine 

 enough to preserve organic markings, have trails and casts of marine worms, and 

 also contain seaweeds, one a Palaeochorda or allied genus, the other a weed with a 

 fiat frond similar to Buthotrephis. That these beds are marine is clearly shown by 

 the great numbers of spicules of hexactinellid sponges which they contain. 



About 350 feet above the base, where the measures are flaggy, tracks of annelids 

 are again abundant. Besides the smaller trails and burrows, there are frequent 

 tracks of a marine animal, possibly a worm, similar to the markings on the Fucoidal 

 sandstone of Sweden, which, by Prof. O. Terrell, have been referred to the geuus 

 Psarnmichnites. A very similar track, with corresponding casts, occurs on the sur- 

 faces of the purple streaked sandstones (Assise 3) of Band 6 in Division 1, of the St. 

 John group, and a similar trail occurs as high up as the lower band of Division 2 of 

 that group. Above this point, such markings have not been found, though the kind 

 of rock — flags and slates — is favorable to their occurrence. The flags of the middle of 

 Division 2, of the St. John group, seem to be the horizon of Cruziana semiplicata 

 (Salter) and C. similia (Billings) ; but I have not found them here. 



About 100 feet or more above the horizon where Psarnmichnites appears, separated 

 from it by a Conglomerate, indications of the Olenellus fauna show themselves. 

 These consist of Volborthella (a chambered cell resembling an Orthoceras), the cysti- 

 dean genus Platysolenites, Pander, and a large Obolus, allied to Michivitzia (formerly 

 Obolus? or Lingula?) monilifera, Linrs., of the Eophyton sandstone of Sweden and 

 the upper part of the " Blue Clay " of Russia. Some of the layers iu this part of the 

 series abound in soft green grains similar to the glauconite grains of the Cambrian 

 rocks in Russia. The paste enveloping them is red. 



A. number of beds between this point and the top of the Basal series contain worm- 

 casts and burrows, and some have remains of small strap-like seaweeds. 



Id summing up the facts bearing on the comparative age of this part 

 of the Cambrian rocks in Acadia we get no aid from the typical genera 

 of this horizon, Olenellus and Mesonacis, but tbe Acadian rocks con- 

 tain other genera of this fauna which serve to fix their age with a cer- 

 tain degree of accuracy. Some of these genera, however, are such as 

 may have a wider range of existence in time than the trilobites, and 

 therefore are not of the same homotaxial value. The trilobites that do 

 occur are not so definitive as some others. 1 



In his latest table of classification Mr. Matthew arranges the Cam- 

 brian System as it occurs in Acadia as follows : 2 



Localities. 



D. — Upper Cambrian (Potsdam series) Unknown. 



C. — Middle and Lower Cambrian, Acadian series St. John, etc. 



B. — Lower Cambrian, Georgian series C. Breton. 



A. — Basal Cambrian, Etcheminian series St. John, etc. 



•Op. cit.,p.l43. 



8 On the classification of the Cambrian rocks in Acadia. No. 2. Canadian Record of Science, vol. 3, 

 1889, p. 310. 



