290 
THE GEOLOGIST. 
the contrary, tlic two single Leptfense, Avhich may, perhaps, be rc- 
gai'ded as inhabitants of a somewhat deeper zone, both recm-. 
Although, accoi'ding to these Hsts, the Caradoc and Bala strata con- 
tain six Discina), foui" Ling-ula;, and one Trematis as true inhabitants 
of shallow water, they are all different to the shallow- water inhabitants 
of the Llandeilo beds, as also are the eight Annelida of the Llandeilo 
diflerent from the eight Annelida of the Caradoc and Bala beds. The 
fauna of the littoral zone has been changed ; the few inhabitants of 
deeper zones which have been found in the Llandeilo beds rise un- 
changed in the following beds. I cannot think of speaking more on 
British Brachiopoda to you. I have only thought these lines neces- 
sary for the sake of showing you that the apparent mixture of both 
gi'oups in your Silurian beds does not seem to me an argument 
against my views ; and as I have now given you two examples in 
which the shallow-water inhabitants were changed, the fauna of the 
deeper zones remaining the same, viz., by the comparison of the 
Utica slate with the Hudson river group, and of the Llandeilo with 
Caradoc beds. I believe I must point out the very nice example of 
the contrary given by youi" uppermost Silm-ian beds. Here you see 
the sea getting gradually shallower, and out of about thirty species 
of Brachiopoda known in the Ludlow beds, you only see a single one 
rising up into the littoral or sub-littoral passage-beds, and occuriing 
there in great numbers, and that is Lingula cornea. Professor 
Phillips has given a great number of data on these facts, and I 
see from his paper on the Malverns, that Rijnch. nucula and Clionetes 
lata sometimes go a good way up, together with Discma rugata, but 
■without continuing into the true passage-beds. 
in. Bohemia. 
Mr. Barrande's Protozoic slates G, containing the first or primordial 
fauna, have hitherto only yielded one Discina and one Orthis as repre- 
sentatives of our class. 
The second or lower Silurian fauna forms Mr. Barrande's ctage D, 
which is divided by this gentleman into five minor gToups, viz. ; — 
d 1, Slates at the base of the etage, near Komarow. 
d 2, Quartzite of Mount Drabow. 
d 3, Black, foliated slates. 
d 4, Very micaceous slates. 
d 5, Yellowish grey slates. 
The lower part of this Stage is very poor in Brachiopoda, d alone 
having yielded the genus Orthis. As to 4 and d 3, M^ Barrande 
has had the extreme kindness to communicate to me the lists of the 
Brachiopoda known to him up to the present time from these beds. 
I see from them that, making absti action of several incomplete spe- 
cimens, most of which, according to this distinguished palreontologist, 
will prove to be Orikidce, d 4 has given thirteen species, viz., two or 
