316 PROCEEDING? OF THE AMERICAN ACADEMY 



than to remark that the specimens agree more closely with Barrande's 

 P. spinosus than with any other form which I have seen figured or 

 described. 



" The rock in which these fossils occur is a compact, dense, rather 

 fine-grained silico-argillaceous slate or slaty sandstone, containing 

 little or no carbonate of lime. In the quarry it displays two sys- 

 tems of joints, in one of which are seen the usual parallel markings 

 due to the movement of contiguous surfaces upon each other under 

 pressure, and it is much broken up by irregular cleavage planes. 

 The strike of the beds appears to be about N. 70° E., and their dip 

 towards the north and west at an angle of about fifty degrees. The 

 narrow belt of slates and grits, of which the fossiliferous strata form 

 a part, extends for some distance towards the north and east, and has 

 also, it is said, been traced for several miles in the opposite direction. 

 But as yet the discovery of fossils has been confined to the one 



locality. 



" In crossing the belt either towards the northwest or in the oppo- 

 site direction, we find the slates and grits to become more indurated 

 and otherwise modified, after which, passing into beds of a semi-crys- 

 talline character, they give place to ranges of sienite. Thus the fos- 

 siliferous belt in this part of its course is actually included hetioeen 

 great masses of igneous rocks ; and it is not a little surprising, that, 

 under conditions so favorable for metamorphic action, the fossil im- 

 pressions should have been so well preserved. 



" In regard to the distribution of the genus Paradoxides, Barrande, 

 in his great work the ' Systeme Silurien de la Boheme,' has the fol- 

 lowing important observations : — 



" ' In Bohemia the genus Paradoxides characterizes exclusively the 

 primordial Fauna, and does not extend beyond our protozoic schists 

 (C). The twelve species which we have determined divide them- 

 selves almost equally between the two slaty belts of Ginetz and Skrey, 

 and two are common to them both. In these two belts we find P. spi- 

 nosus in all the localities which have afforded fossils, while each of 

 the other species is restricted to a ^e\w points, principally those of 

 Ginetz and Skrey. 



" ' In Sweden the Paradoxides belong exclusively to the local for- 

 mations designated by Angelin as Regions A and B, representing 

 jointly our protozoic slate formation (C) above mentioned. The 

 recion A is the lowest fossiliferous belt of Sweden, as it rests directly 

 on the azoic rocks. 



