331 ANNUAL OF SCIENTIFIC DISCOVERY. 



" In Sweden the Paradoxides belong exclusively to the local formations 

 designated by Angelin as regions A and B, representing jointly our protozoic 

 slate formation above mentioned. The region A is the lowest fossiliferous 

 belt of Sweden, as it rests directly on the azoic rock. 



"In Great Britain we know, according to the papers of Mr. Salter, that 

 Paradoxides has been found in the Trappean group (Lingula flags of the 

 Survey) which is the oldest fossiliferous rock of Wales, resting on the azoic 

 sandstones of Haiiech and Barmouth. There is, therefore, a perfect agreement 

 in these three regions as to the geological horizon of the genus now under con- 

 sideration. This agreement acquires still further importance from the affini- 

 ties displayed equally and everywhere by the other types which accompany 

 the Paradoxides ; for instance, in Sweden we have olenus and conocephelites, 

 in England olenus, as recognised in the Trappean group." 



As thus the genus Paradoxides is peculiar to the lowest of the paleozoic 

 rocks in Bohemia, Sweden, and Great Britain, marking the primordial division 

 of Barrande and the Lingula flags of the British survey, we will probably be 

 called upon to place the fossil belt of Quincy and Braintree on or near the 

 horizon of our lowest fossiliferous group, that is to say, somewhere about the 

 level of the primal rocks, the Potsdam sandstone, and the protozoic sandstone 

 of Owen, containing dekelocephalus in Wisconsin and Minnesota. Thus, for the 

 first time, are we furnished with data for fixing conclusively the paleozoic age 

 of any portion of this tract of ancient and highly altered sediments, and what 

 is more, for defining, in regard to this region, the very base of the Paleozoic column, 

 and that too by the same fossil inscriptions ivhich mark it in various parts of the 

 old world. 



Referring to the occurrence of Paradoxides in the protozoic rocks of Europe, 

 Barrande observes: "The presence of this genus has not been satisfactorily 

 proved in any other Silurian region, although this generic name has been 

 applied to North American forms, such as Paradoxides Boltoni, and Par. 

 Harlani, &c. The first of these is known to be P. Lichas, and we know nothing 

 of the others. The care with which the geologists of New York have 

 described the Trilobites of the lower Silurian rocks of the country in question, 

 is sufficient proof that they have not discovered any trace of Par." 



I may add to this, that in no subsequent publication have I seen any 

 reference to the finding of fossils of this genus hi the rocks of North America. 



One of the most curious facts relating to the Trilobite of the Quincy and 

 Braintree belt, is its seeming identity with the Par. Harlani, described by 

 Green in his monograph of North American Trilobites. This description, 

 which is quite imperfect, was made out from a specimen of unknown locality 

 procured some twenty-five years ago, by Dr. Harlan, from the collection of 

 our well known mineralogist, Mr. Francis Alger. That it is the same with 

 the more conspicuous of our Quincy fossils, is I think established by the 

 comparison of the nearly complete specimen of the latter with the cast of Par. 

 Harlani taken from Mr. Alger's specimen, the original never having been 

 returned. Considering the perfect agreement in lithological characters of the 

 matrix a.s described by Green, with that of the Quincy fossils, and the imme- 

 diate recognition of this identity of mineral features by Mr. Alger on seeing 



