154 ROMER’S DESCRIPTION OF THE CHALK 
also the oldest Anatifa. Of Crabs, the Jurassic genera Glyphea 
and Kilytia (?) continue in the chalk, and there become extinct: 
with them Palemon (?) is associated, and, it would appear, the 
still living genus Calianassa. 
If we now turn to the remains of the more highly developed 
animals, we find these not to be very numerous. As yet scarcely 
thirty species of Fishes have been discovered: but they belong to 
the four principal divisions ; and, what is most remarkable is, 
that recent genera, for instance Beryz, should likewise occur 
amongst them; others appear in the older rocks. The Saurians 
are still more rare, the remains of three species only having been 
discovered; but no traces of Birds and Mammalia have been 
hitherto detected. 
The creation of the chalk period approaches considerably to 
that of the present epoch, in the absence of older forms, and 
the reception of others which are more recent; but it still ap- 
pears to be as much distinguished from the modern epoch as 
the older formations, no decided species of the chalk having 
hitherto been proved with certainty to exist in any other for- 
mation. That the climate of the chalk period was much 
warmer in our latitudes than at present, can scarcely be main- 
tained from the fossils, since only the large Sawrians and some 
Cycadee afford ground for the supposition. 
ConcLusion. 
Having now become acquainted with the numerous and varied 
fossils of the chalk formation of the north of Germany, and with 
their assistance established the relative age of the strata in which 
they are imbedded, it will be apparent that this formation is here 
so rich, that but few other regions can show an equal variety. 
The principal results of our geognostic researches, we trust, 
will be recognised as correct. The main points for subsequent 
investigation will be, —To ascertain Whether the mass of rock be- 
tween Recklinghausen and Haltern belongs to the lower green- 
sand or to the upper chalk marl ?—Whether the gault does not 
occur in several other districts >—Whether the Hils-clay is really 
older than the Hils-conglomerate ?—Further ; Of what age are 
the more recent sandstones of the “ Saxon-Switzerland,” accord- 
ing to their fossils ?—and, In what relation does the entire north 
European chalk formation stand to that of more southern dis- 
tricts, especially to the Nummulite and Hippurite limestones ? 
