426 Forty-second Report on the State Museum, 



P. (S.) orthostoma, Barrois, aff. P. turbinate), U. H. 

 P. (S.) naticopsis, CEhlert, aff. S. globoso, L. H. 

 P. (S.) Giebeli, Kays., cnf. P. Billingsi, L. H. 



P. trilobatum, L. H. 



S. Fitchi, L. H. 

 Cyclonema Guillieri, (Ehl., cnf. C. Doris, S. G. 



Trilobites: 



Proetus fallax, Barr., cnf. P. Kowi, Ham. 



P. Ligeriensis, Bariois, aff. P. curvimarginato, S. G. 



P. cornutus, Gold., aff. P. canaliculato, U. H. 



This striking array of specific affiliations involving suggestions of 

 analogy or identity in nearly twenty-five per-cent of the Erbray 

 species with American forms and the great majority of these with 

 Lower Helderberg species, circumstances similar, though actually 

 much stronger than those which had induced Kayser and his followers 

 to refer the Lower Helderberg fauna to the lowest Devonian, has not 

 led Barrois to the same conclusion. On the contrary, in the face of 

 this showing, he is disposed to regard the Erbray fauna as parallel to 

 the Hercynian and etage G, the Oriskany and, in part, the Upper Hel- 

 derberg, standing as equivalents thereof, while the etage F, with the 

 Lower Helderberg as its parallel, is relegated to the top of the Silu- 

 rian. The Waterlime is incidentally considered as a distinct fauna 

 equivalent to the Tilestones. 



In this respect the author appears to us (irrespective of personal 

 convictions in regard to the validity of all the data) not to have fully 

 faced the facts and indeed his somewhat different position, assumed 

 on page 319, appears in a certain degree more harmonious. There it 

 is held " that the three etages Konieprusian, Gedinnian and Coblenzian 

 constitute the passage between the Upper-Silurian and the Lower- 

 Devonian;" (the Konieprusian equaling F= Lower Helderberg, the 

 Gedinnian, G = Oriskany — Upper Helderberg, partim = Hercy- 

 nian=Erbray, the Coblenzian, H = Upper Helderberg partim.) 



The reasons for this conclusion, to us at least, are somewhat 

 obscure, as we find in the matter of detailed specific analogies and 

 faunal ensemble, closer analogy in the calcareous Hercynian of the 

 Hartz and Erbray, and the Lower Helderberg, than in those faunas 

 and that of the Upper Helderberg. Furthermore, the suggestion of 

 Barrois, that the Oriskany and Upper Helderberg (i. e. essentially 

 Corniferous) faunas stand in the same relation to each other as the 

 quartzite of Plougastel and the Erbray limestones, i. e. arenaceous 

 and calcareous facies of the same faunal assemblage, will not afford 

 complete satisfaction. 



