290 EMMERICH ON THE MORPHOLOGY, CLASSIFICATION 
(Calceola, &c.). These have also been met with in the other 
German transition limestones. It is remarkable that none of 
the Eifel Trilobites of the palzeozoic rocks have as yet been met 
with on the right shore, with the sole exception of Ph. macroph- 
thalmus. Of this species I only know two places on the right 
shore where they are found, Cromford in the north, (south- 
west of Elberfeld), and the roofing-slate of Wissenbach near Dil- 
lenburg. This slate follows immediately upon a grauwacke con- 
taining Homalonotus, being itself overtopped by a limestone 
containing Eifel fossils, but without Trilobites, and separated by 
a second, more earthy slate formation, the Posidonomya slates 
of Herborn. The Calym. equalis, evidently allied to the genus 
Phillipsia, favours considerably the referring the Herborn slate 
to the lower coal formation. Dr. Beyrich discovered the fre- 
quently mentioned facetted-eye Phacops (cryptophthalmus, per- 
haps identical with the Devonian /evis) in the goniatite lime- 
stone of Obenscheld, likewise near Dillenburg. The same species 
is found in the Cytherine slate not far from Weilburg, accord- 
ing to a specimen with which I was kindly made acquainted by 
M. Althaus. The last Rhenish deposit of Trilobites known to 
me, is that occurring in a white genuine mountain or carbo- 
niferous limestone at Ratingen, abounding in Producte. The 
As. Daimani, G., confirms likewise in the present instance the 
regular distribution of the Trilobites in the series of strata; it 
also belongs to the genus Phillipsia, peculiar to the mountain 
limestone. The same fact is also confirmed by the last German 
locality of Trilobites worthy of remark, viz. the Falkenberg de- 
posit resembling grauwacke in the county of Glatz. The Grif- 
jithides obsoletus, Phill., of the mountain limestone of York 
occurs here, associated with numerous Producte; the caudal 
shield of another Trilobite found in this deposit belongs to the 
same genus, or to Phallipsia. 
If, in conclusion, we draw in all briefness the final result 
accruing from the above researches on the distribution of the 
Trilobites in the European strata of rocks, we arrive at the con- 
viction that there is scarcely any other family of the animal 
creation more calculated than that of the Trilobites for the cha- 
racterisation and determination of the various members of the 
palzozoic rocks. The ease with which the species and genera 
are distinguished by striking characters, and their slight vertical 
extension in the strata, which, on the other hand, is very great in 
Vv 
