402 The American Geologist. June, i897 
These comparisons might.be extended, but I think they are 
sufficient to show that OleneJlus asaphoides (the JSlliptoceph- 
ala asaphoides of Emmons) with its associated fauna, above 
described, must be placed in the Paradoxides zone. 
We come to speak now of the Olenellus fauna, namely, the 
forms associated with the trilobites to which the name Ole- 
nellus was originally given by Hall, and here we meet with 
greater difficulty because we fin^d fewer characteristic species 
comparable with those of the Paradoxides beds. We may, 
however, offer some broad generalizations. 
The genus Ptychoparia is one which enters largely into this 
fauna, so we find no less than eight species referred to it (two 
doubtfully). The genus is one which in typical, or in 
nearly related forms, ranges through the Cambrian sys- 
tem, but it is not reported from the Newfoundland pre-Para- 
doxides beds, nor does it so occur in England or Scandinavia. 
One example is reported from Bohemia in a conglomerate im- 
mediately beneath the Paradoxides beds. This genus does 
not indicate a pre-paradoxidean age, for the beds in which it 
may be found — at least where the remains are abundant. 
Olenoides marks a group of trilobites very like Dorypyge of 
Dames, a Cambrian genus found in China, which, with its 
associated genera, Dames compared to the fauna of the An- 
drarum limestone of Sweden (Upper Paradoxides beds). In 
Zacanthoides we have a type of trilobite comparable with 
Middle Cambrian forms of western America. Prot.ypas hitch- 
cocki will bear comparison with Ullipsocepholtis germari of 
the Paradoxides beds of Bohemia, and Pompeckj describes a 
Protypus (an obscure example) from a conglomerate at the 
base of the Paradoxides beds in that countr3\ Protypus hitch- 
rocki and P. senectus are not of the same genus. P. senectus 
is a Dolichometopus, a genus characteristic of the Andrarum 
limestone (Upper Paradoxides beds). 
Something may be said also of the brachiopods, though as 
a rule the genera of this class have a wide vertical range, and 
so are of less value for close correlation. Among these the 
common occurrence of orthids would indicate that the range 
of the Olenellus fauna was not much below Paradoxides. In 
very few countries have orthids been found below this zone. 
In Bohemia the genus has been found in the conglomerates 
