424 Forty-second Report on the State Museum. 



mass of Capulids, which again show many affiliations with the Hartz 

 and Bohemian species." 



From the foregoing (making suitable allowance, in some of the 

 comparisons, for the progress of knowledge since the date of this 

 writing), it appears that both the Lower and Upper Helderberg 

 groups, and to a certain degree the arenaceous deposits separating 

 the two, enclose faunas which are closely allied to those of the oldest 

 formations of the Hartz and their equivalent series of beds in 

 Bohemia. 



Moreover, the American faunas in question demonstrate that in all 

 their leading features they are Devonian, more strongly so the higher 

 we ascend, although in occasional particulars, like the European 

 Hercynian faunas, they reveal many peculiarities suggestive of Silurian 

 characters. 



In 1884, Kayser, having altered his view in regard to the base of 

 Bohemian Devonian, paralleled the Lower Helderberg with F 2 , the 

 Oriskany and Upper Helderberg with G, placing the Waterlime and 

 Tentaculite limestone as the equivalent of the Ludlow, parallel to F r 



Novak having shown in 1880 that the etage F was not divisible 

 except in to varying facies of one fauna, Freeh, in 1887, regarded 

 the Waterlime as equivalent to E 2 (Ludlow, Up. Sil.), the remainder of 

 the Lower Helderberg and the Oriskany as different facies of the same 

 horizon (=F 1 + 3 , lowest Lower-Devonian), the Cauda-galli and Scho- 

 harie grit as the upper part of the Lower-Devonian the Corniferous 

 as lower Middle-Devonian, the Upper Helderberg group generally, 

 being the essential equivalent of the Etage G, G 2 . 



Barrois's (1889) description of the Erbray Hercynian fauna gave 

 rise to the following comparisons with American species: 



Brachiopoda : 



Strophomena hercynica, aff. S. varistriatse, L. H. 

 Ambocoelia umbonata, Conrad, cf. Sp. modestus, L. H. 

 Orthis palliata, Barr., aff. Orth. pereleganti, L. H. 

 O. striatula, Schl., aff. O. multistriatse, L. H. 

 O. vulvarius, Schl., aff. O. multistriatse, L. H. 



O. Tulliensi, Ham. 

 Pentamerus Sieberi, Buch., cnf. Pentam. Verneuili, L. H. 

 Pentamerus galeatus. 



Rhychonella amalthoides, Barrois, cnf. R. acutiplicata, L. H. 

 R. nympha, Barr., aff. R. Campbellanse, L. H. 

 R. cognata, Barr., aff. R. bialveatse, L. H. 

 R. princeps, Barr., cnf. R. mutabilis, L. H. 



