SUESS — DlSTKinUTION OF TUE lillAClIIOPODA. 
291 
Ihree Discmee, one Lingula, five Orthides, two Lcptoence, and two 
doiihtf'ul species. You remark exactly the same association of tlio 
shallow-water ^-oup A ^vith the intermediate forms, which I have 
already pointed out several times. 
M. Barrande knows thirteen or fourteen species of Brachiopoda 
from d 5, one of which is Discina scrohiculosa from d 4, one or two arc 
Liutjulo}, {our Orthides, and four other Stfophomenidce, among which is 
the recurrent Lept. aquila, and two doubtful species. I need not say 
that it is again a quite similar association, excluding the formation 
from deep sea condition. Finally, M. Ban'ande has a short time ago 
mentioned a new Lingula in chloritic quartzite belonging to etage D. 
Now it is the bed d 4 which, as M. Ban-ande has taiight us, con- 
tains intercalations of slates with calcareous nodules, which have 
yielded four new species of fossils, four species identical -with those of 
etage B, and not less than sixty species which have never been found in 
d 4, nor even in (Z 5, but only in the overlying Upper Silurian etage 
jEj. Among these sixty species ai'e eleven Brachiopoda : Terehmt. 
Daphne, T. liiiguafa, T. monaca, T. oholina, T. ohovata, T. reticidaris, 
Spirifer togatus, Orthis mulus, Lept. eughjpha, L. patricia, and L. 
Haueri. Not one member of the shallow-water group A, and only 
one single Orthis are among these eleven species, several of which are 
Spirifcridcv ; T. Daphne is a Rhyyiclionella. In this Hst the predomi- 
nance of gi'oup B is, indeed, very clear. 
As, I believe, M. Barrande's suggestion is now generally acknow- 
ledged, that the fauna d 4, and at least a part of the Upper Silui'ian 
fauna E must have lived at the same time, I presume, further, that 
tliis part of the fauna E must have lived in a somewhat deeper part 
of the sea than the contemporaneous littoral or sub-littoral fauna d 4 
and d 5, and I regard these " colonies" as the intercalations of the 
deposits of a somewhat deeper bathymetrical zone between sub- 
littoral deposits. 
In perusing that highly instructive comparison between the 
Silurian beds of Bohemia and Scandinavia, which M. Barrande pub- 
lished a few years since, it is seen that the primordial faunse of both 
countries consist of very closely representative, but not identical, 
species.* The same is the case yv\th the second or lower Silurian 
fauuffi, although here, perhaps, a small number of identical species 
may be found. The comparison of the third or Upper Silm'ian fauna) 
yields quite another result, as the number of identical species in both 
countries is by far greater, although small in comparison to the 
locahty of these fauna3. M. Barrande teaches that with few excep- 
tions (one Trilobite, two Orthocerata, and a somewhat greater number 
of Corals), these identical species belong to the class of Brachiopoda, 
not less than eighteen of which are enumerated as occurring simul- 
taneously in the Upper Silurian beds of Scandinavia and Bohemia. 
I suppose eight of them to be Spiriferidce, three Ehijuchonellidce, and 
seven Strophomenidce, among which are two Orthides. The group A is 
* Perhaps with one single exception. 
