How is the Cambrian divided 2 479 
The third fauna contains the following genera: 
Liostracus ? Leptoplastus. 
OLENUS Eurycare (s. gen. of Leptoplastust 
Parabolina (s. gen. of Olenust). *Agnostus. 
Here all the genera and subgenera are peculiar to this 
fauna except the ubiquitous Agnostus and Liostracus ? 
But the connection with the next fauna is closer than 
appears from the names, as some of the genera are closely 
related to those of the succeeding fauna. Hurycare especi- 
ally is intermediate between Leptoplastus and Ctenopyge. 
The fourth fauna has the following genera : 
*Cyclognathus (sub-gen. of Pel- Ctenopyge (s. gen. of Leptoplas- 
tura Ty) tus f) 
PELTURA. Sphexrophthalmus (s. gen. of Lep- 
, Protopeltura (sub-gen. of Pel- toplastus +) 
tura Tt) Boeckia (sub. gen. of Leptoplas- 
Acerocare (sub-gen. of Peltura +) tus.) 
* Agnostus. 
Cyclognathus is found also in afauna above, but Peltura- 
and Ctenopyge, with their related forms, especially mark this 
horizon. 
The fifth fauna, which has a strong Ordovician facies, 
exhibits the following genera: 
Cheirurus. Nileus. 
Pliomera. Symphysurus (s. gen. of Nileus }) 
* Harpides. Niobe. 
Remopleurides. ° Holometopus. 
* Triarthrus. Conophrys. 
° DICBLLOCEPHALUS ° Parabolinella (s. gen. of Olenus.+) 
° CERATOPYGE. Amphion. 
° Buloma Ampy2. 
Megalaspis ° Agnostus. 
a 
Among these eighteen genera there are only about eight 
(marked by “°”’) which by their aspect recall the Kuropean 
types of the Cambrian trilobites, and probably for this 
+ See Brogger’s Etagen 2 und 3. 
MA 
