﻿S. W. Ford — Age of the Swedish Paradoxides Beds. 475 



Corynexochus, Agnostus, Hyolithes, Orlhis, Lingulella, Obolusf, 

 Obolella ?, Acrotreta, Acroihele, Kutorgina and Iphidea. Of these, 

 two, Orthis Hichsi and Obolella f sagittalis, are well-known 

 Welsh Menevian species. A considerable number of the gen- 

 era of the Swedish measures are wanting in the British Mene- 

 vian beds, and vice versa ; but this, I think, is no more than 

 might be reasonably expected in the case of so widely sepa- 

 rated exposures of the same formation. 



In view of the above facts, I think we may assume with a 

 very considerable degree of confidence, that the Swedish Para- 

 doxides beds, or at any rate those above the Division character- 

 ized by Paradoxides Kjerulfi, are of the age of the Menevian 

 group ; and the question arises whether there is anything in 

 the aspect or structure of this species to prevent the division 

 in which it occurs from being also regarded as Menevian. In 

 an earlier paper (this Journal for October, 1881), I have dis- 

 cussed at some length the structure and relations of this spe- 

 cies ; and I see no good reason at present to modify the opinions 

 concerning its affinities therein expressed. The view I took at 

 that time was, that P. Kjerulfi, although confessedly an aberrant 

 form, should nevertheless be regarded as a Paradoxides. There 

 are a number of strong points of resemblance between this 

 species and P. olandicus Sjogren,* judging from the figures 

 which I have seen of these forms; and that the latter is a true 

 Paradoxides I think admits of no question. The Swedish 

 Paradoxides, like those of the typical Menevian beds, and un- 

 like those of Bohemia, are all, so far as determined, of the 

 Brachypleural type ; i. e., have all of their anterior pleura of 

 the same relative length in the fully developed or adult forms ; 

 but whether this is true of the particular species P. Kjerulfi is 

 not at present known. I have elsewhere presented reasons for 

 believing that the Brachypleural species of the genus Paradoxides 

 are more recent than the Macropleural, based upon facts fur- 

 nished by the Life History of Olenellus asaphoides. Mr. Matthew, 

 in speaking of the American specimens of P. Kjerulfi, says 

 that the glabella is not enlarged in front as in the true Para- 

 doxides ; but the figures given by M. Linnarsson show that in 

 the Swedish specimens, or at any rate, in those illustrated, it is. 

 He further says that the position of this species (which he 

 calls, upon the authority of Professor Brogger, Olenellus (?) 

 Kjerulfi) in Europe, "is beneath that of the beds carrying 

 Paradoxides ; " but until it is proved that P. Kjerulfi is not a 

 Paradoxides, it seems the better course to sav this its position 

 in Europe is at the base of the Swedish beds carrying Para- 

 doxides. 



* Geol. Foren. Forhandl., Bd. i, p. 72, t. 5, fig. 1, 1872. 



