740 CHARLES SCHUCHERT 



crassicosta (these shells look more like Plethorhyncha speciosa) 

 Trigeria ( ?) oehlerti (Leptocoelia with excessive fold and sinus), 

 Tropidoleptus carinatus rhenanus, Megalanteris, Spirifer primaevus 

 (type of S. murchisoni). The following remind one strongly of the 

 Maecurii facies: Actinodesma, Cypricardella, Leptodomus, Goniophora, 

 Grammy sia (large forms), Modiomorpha (large forms), Sphenotus, 

 Pteronites, Limoptera^ Cryphaeus, and Homalonotus. 



For a modern work on this fauna, see Dreverman, Palaeonto- 

 graphica, Vol. L (1904), pp. 329-87, 5 plates. Even a glance at 

 these plates will lead American workers to see an earher development 

 of their Hamilton fauna. European stratigraphers invariably regard 

 the Siegan as Lower Devonic. 



Compared with North America, the Amazon Devonic, according 

 to Katzer, proves to be a mixture of Oriskanian, some Helderbergian 

 and more especially New York Hamilton. Formerly Katzer regarded 

 all the Devonic of the Amazon as Middle Devonic. He now con- 

 siders that the Hamilton cannot be considered as uppermost Middle 

 Devonic, but that part of it must be referred to the Lower Devonic — 

 a view in which he will have few, if any, followers. This conclusion 

 is largely based on the early occurrence in South America (Maecuru) 

 of Vitulina pustulosa, Tropidoleptus carinatus^ large Grammysia, 

 Leioptera, Actinoptera of the hoydi type, and the high or Hamilton 

 occurrence of these types in North America. 



Katzer's dithculties would have vanished if he had correlated the 

 Maecuru and Curua deposits with the Oriskany of the Lower Devonic. 

 That this correlation is a more accurate one is borne out by the fauna, 

 as has been shown by the present writer. 



It has also been shown that the Erere fauna has not the facies of 

 the Onondaga nor of the Hamilton. This dissimilarity is partially 

 explained by the Amazon coarse Httoral deposits, an unnatural 

 habitat for an extensive coral fauna as that of the American Middle 

 Devonic. However, the Erere fauna is wholly a direct outgrowth of 

 that of the Maecuru, while the Onondaga (Corniferous) is a develop- 

 ment out of the Oriskanian of the type of the northern province plus 

 an eastern North Atlantic invasion (the Spirifer cultrijugatus fauna 

 of the Rhine at the base of the Middle Devonic), and another from 

 the south through the Mississippi embayment bringing in some of the 



