280 
THE GEOLOGIST, 
Imperinl Museum of Mineralogy, Vienna, April "30, 18G0. 
Mv Dear Friend, — I bog leave to submit to your kind judgment 
the leading views of my second paper on the distribution of Brachio- 
poda, published by our Academy a short time ago. 
In a fii'st paper on this subject, I have tried to unite the facts relat- 
ing to the geographical and bathymetrical distribution of living Bra- 
chiopoda, and have arrived at the conclusions : 1st, That the geo- 
logically ancient genera (Terebratula, Rhynchonella, &c.), are sporadic, 
and only some genera of newer date (Krausina, Morrisia) may, 
perhaps, be termed endemic genera ; 2nd, That Brachiopoda are found 
living in every climate, but that the genera with translucid shells 
(Lingula, Discina) are confined to warmer seas ; 3rd, That these 
same genera with translucid shells are only found within very 
moderate depths, most of them within seven fathoms, the genera 
with opaque shells (Terebratula &c.) inhabiting, on the contrary, 
greater depths, with a very small number of exceptions. Some of 
these latter live even in very considerable depths. 
My subsequent papers were intended to give my views on the 
habitations of fossil Brachiopoda, and so I have given a chapter at 
the beginning of my second paper, which contains some general 
remarks on the life of species, and on the influence of a change of 
external conditions on the distribution of animals. It is not this part 
of my paper I wish to speak of now ; if you should wish for it, I 
might give you an analysis of it in some other letter, and you would 
find a new classification of our Tertiary beds in it. Before I enter 
into further details, it is sufiicient to extract the following conclusions 
from this chapter : — 1st, A change of level, which pi'oduces an 
extension and communication of marine provinces, will produce dimi- 
nution and isolation of terrestrial provinces, and vice versa. 2nd, 
Because the vei-tical range of bathymetrical zones increases with the 
depth, an oscillation may produce greater changes in the upper than 
in the deeper zones. Besides this, the littoral and sub-littoral zones 
are exposed to certain influences, which do not penetrate into the 
deeper zones, so that external changes may cause great variation in 
the upper zones, the fauna of the deeper sea remaining the same. 
1853. — " On tlie Brachial Apparatus of Thecidea." Acad. 8vo., three plates. 
1854. — " On the Brachiopoda of Kosseii Strata. Acad. 4to., fom* plates. 
1853. — " On the Brachiopoda of the Hallstatt Strata." Acad. 8vo., two plates. 
1856. — " German edition of Davidson's Classification of the Brachiopoda." 
4to., five plates. 
1858. — " On the Brachiojooda of Stramberg Strata in Haner's Beytrage." 4to., 
six plates. 
1859. — " Note sur la Waldhemia Stephaiiis in Palocon." Lomb. 4to., one 
plate. 
„ . — " On the Distribution of Brachiopoda." First paper. Acad. 8vo. 
,, .- - „ „ „ Second paper. „ „ 
In addition to these, Prof Suess has published several other papers relatmg to 
the Geology of the Alps, etc. 
