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Classification of Cambrian Rocks. 313 
Tt has been stated in the notice of the meetings of the 
Geological Congress in London (1888) that Mr. Walcott’s 
fauna of Olenellus, of forty-two genera, and 113 species,’ 
is of earlier date than the Paradoxides bed, but from Mr. 
Walcott’s own observations in the West, it is evident that 
this fauna should be divided, as only the Olenellus-Dorypyge 
phase can with certainty be placed below the Paradoxides 
zone. 
In order to show the characteristic species of the Olenellus 
Bathyuriscus or later fauna of Olenellus, the writer has 
selected the following species, which, according to Mr. 
Walcott, belong to this horizon. 
The genera marked with an asterisk, are found in the 
Paradoxides beds. 
* Protospongia fenestra. O. spinosus. 
* Eocystites (2?) longidactylus. O. typicalis. 
*Tingulella Ella. * Ptychoparia Housensis. 
*Kutorgina pannula. *P. Kingi, (Anomocare.) 
* Acrotreta gemma. *P. prospectensis (**) 
* Acrothele subsidua. *P. quadrans _(‘*) 
*Orthis Highlandensis. Crepicephalus Augusta. 
*Stenotheca elongata. C. Liliana. 
* Hyolithes Billingsi. Protypus senectus, (cf. Ellipso- 
*Leperditia Argenta. cephalus.) 
* Agnostus intercinctus. Bathyriscus Howelli, (cf. Ogygia.) 
Olenellus Gilberti. B. producta, C=): 
Olenoides levis. Asaphiscus Wheeleri, (cf. Niobe.) 
O. Nevadensis. 
Among these species, Acrotreta gemma and Acrothele sub- 
sidua are similar to species of the Paradoxides beds. Ag- 
nostus intercinctus is a good example of the group of the 
Longifrontes, which has many species in the Upper Para- 
doxides beds, and some in the Lower. Protospongia fenes- 
trata is a species of the Lower Paradoxides beds. Of the 
four species of Ptychoparia, three would by Swedish geolo- 
gists be included in the same genus with Anomocare microp- 
thalmum, also of the Paradoxides beds, and there are other 
' See Bull. U. 8. Geol. Survey, No. 30, p. 45. 
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