MIDDLE DEVONIAN ROCKS. 
451 
Fig. 510. 
Clymenia linearis^ Munster. Petherwyn, Corn¬ 
wall ; Elbersreutli, Bavaria. 
Fig. 511. 
Cypridma serrato-striata^ 
Sandberger, Weilbnrg, 
etc.; Cornwall, Nas¬ 
sau, Saxony, Belgi¬ 
um. 
shells, trilobites, and corals, 
enumerated by Mr. Etheridge, 
none of which pass into the Car¬ 
boniferous formation. Among 
the genera we find Favosites^ 
Heliolites^ and Cyathophyl- 
him. The two former genera 
are very frequent in Silurian 
rocks: some few even of the 
species are said to be common 
to the Devonian and Silurian 
groups, as, for example, Fa- 
vosites cermcornis (Fig. 513), 
Fig. 513. 
Favosites cervicornis, Blainv. S. Devon, 
from a polished specimen. 
a. Portion of the same magnified, to 
( show the pores. 
Of the corals 51 species are 
Fig. 512. 
Heliolites porosa, Goldf., sp. {Porites pyri~ 
formis, Lonsd.) 
a. Portion of the same magnified. Mid¬ 
dle Devonian, Torquay, Plymouth; 
Eifel. 
one of the commonest of all 
Fig. 514. 
h 
a. Cyathophyllum ccespitosum., Goldf.; 
Plymouth and Ilfracombe, b. A 
terminal star. c. Vertical section, 
exhibiting transverse plates, and 
part of another branch. 
