IIov^ is the Cambrian divided? — Matthew. 143 
°DicELLOcErHALUs. °Pfl5mJo^me^/a (s. gcn. of Olcnus.f ) 
°CERATorYGK. Anipliion. 
^Euloma. Anijn'x. 
Megalaspis. °Agno8tup. ' 
Among these eighteen genera there are only about eight 
(marked by "°") which by their aspect recall the European 
types of the Cambrian trilobites, and probably for this reason 
the Swedish pala?ontologists regard this fauna as belonging to 
the Lower Silurian. But it evidently corresponds to the 
Tremadoc fauna, which by English palajontologists is reckoned 
to the Cambrian; and late discoveries in America show that 
Nileus, Niobe, ifec, also are truly Cambrian. 
In Wales, which has given its name to the Cambrian system, 
the succession of the faunas, their unity and their relative im- 
portance arc much the same as in Sweden and Norway, but 
these features are obscured by the use of different names for 
some of the genera. 
Mr. Robert Etheridge's catalogues in the Geology of North 
Wales are the basis for the comparisons made here. In them the 
genus Conocoryphe (as used by Mr. Salter) is made to serve 
for a number of Scandinavian and other genera. The figures 
of many of the species in this work are very imperfect, but for 
the purposes of this comparison the species in Conocoryphe 
may be distributed to Conocoryphe, Ctenocephalus^ Liostra- 
cus, Ptychoparia, SolenopJeura, Exdoma^ Paroholina, Para- 
holinella (?) Conocephalites and Dicellocephalus. 
In Wales the first fauna has produced no trilobites unless 
Conocoryphe viola belongs here. The second Cambrian fauna 
has a full representation as follows : 
Paradoxides. Ctenocephalm. 
Plutonia (sub gen. of Paradoxides.) 
Anopolinus. Carausia. 
Solenople ura. Conocoryphe. 
* Liostracus {or Ptychoparia) Erinnys (c.f.) Ilarpides. 
Holocephalina. Microdiscus. 
Arionellus (=A(/raulos.) * Agnostus. 
Here there are twelve genera of which two only extend up- 
ward to higher horizons. 
t See Brogger Etagen 2 und 3. 
