[matthew] CAMBRIAN FORMATION IN EASTERN CANADA 75 



but with many simpler and smaller organisms intermingled. In this 

 subzone calcareous organisms are more abundant than in the shales 

 above and below. 



Of the calcareous forms two species are more abundant than others, 

 Protorthis Billingsi and Eocystites primœvus. These no doubt assisted 

 in adding to the large amount of lime which the shales of this sub- 

 zone contain. 



This subzone is especially the home of Paradoxides for it has 

 furnished at least four species of the genus. By far the most common 

 species is P. Eteminicus, the American representative of P. rugulosus 

 of Bohemia; next in order of abundance is the P. Mic-mac of Hartt, 

 noted for its thin and easily wrinkled and distorted tests; next the 

 rather rare little species P. Acadicus, the only species at this horizon 

 with a granulated test. Another scarce species is the giant P. regina 

 which may be compared in this respect with the large P. Davidis, 

 found by Dr. Henry Hicks in Wales; the pleurae of the Canadian 

 species may be recognized by their great size. The granulated test 

 of P. Acadians seem out. of place in these soft shales, tests of Cambrian 

 trilobites with such surface seeming to be related to harder conditions 

 of environment and coarser sediments, as witness P. cf. Forchhammeri 

 of Cape Breton and Olenellus Thompsoni of Southern Labrador. 



As showing the variation in the composition of faunas due to 

 habitat, we call attention to that of Young's Point. The first col- 

 lections from this place being imperfect led to the fauna being com- 

 pared with those of the Ordovician system; but an examination of 

 the stratigraphy of the district resulted in placing the fauna at the 

 base rather than the summit of the Cambrian system; further col- 

 lections made by Dr. Percy Raymond showed that they were to be 

 regarded as of the Paradoxides zone. The age of this fauna is more 

 fully discussed in a later part of this article. 



ABENACUS SUBZONE. 



The upper subzone of the Paradoxides beds in the St. John basin 

 is characterized by the presence of the species P. Abenacus, which is 

 the American representative of P. Tessini of Sweden ; it is also notable 

 for the abundance of the Agnosti as well as of the Pychoparina;, 

 Ptychoparia and Solenopleura being common genera at this horizon. 

 The shale of this subzone is quite fine in texture and somewhat darker 

 than that of the beds below ; it probably contains more diffused organic 

 matter. 



The limited exposures of Cambrian rocks in the Kennebecasis 

 valley give only imperfect means of comparison of the different mem- 



