Hyatt.] 
28 
[May 16, 
plored, but so far as known, they belong to the same category as 
those of the Northeastern Alps, and are included in the Mediterra- 
nean province, as has been stated previously by Neumayer. There 
is no evidence, so far as I know, which sustains the conclusion, that 
there was a migration of forms of the radical stock or of the radical 
species of the different series of the Arietidse from the south through 
the basin of the Rhone into South Germany. On the contrary, 
the basin of the Rhone contains a fauna, which is almost entirely 
residual and might have been derived by migration from South 
Germany and the Cote D’Or. The faunas to the north of the au- 
tochthonous zone of the Arietidse bear also very strong marks of 
having been derived from those of South Germany or Cote D’Or. 
Thus in Luxemburg, Hanover, and North Germany in general, 
there is a prevalence of the same succession in the beds and simi- 
lar faunas, which indicate a more exact parallelism with those of 
South Germany than has been found in the Northeastern Alps. The 
faunas are, however, less complete, both geologically and palseo- 
zoologically in the lowest beds of the Lower Lias, especially in the 
smoother varieties of Psil. planorbe. In other higher beds there 
is a paucity in the representation of the forms of the different series 
a prevalence of smaller-sized specimens, and a later appearance of 
the radical forms of the different series, which show the basins to 
have been peopled by migrants from the south. 
England also apparently derived its fauna from the south. The 
beds are presented in detail as in South Germany ; but, in spite of 
this fact, there is in that fauna a generally later appearance of rad- 
ical species, and, in fact, with the exception of the more degraded 
species of the Asteroceran series, the fauna does not present any 
forms, which can be said to have originated there. The shells are 
of large size in many species and the surroundings were evidently 
very favorable for the growth of the individual, though not for the 
evolution of new forms. 
Information with regard to the faunas of localities farther north, 
like those farther south than those mentioned above, is not exten- 
sive. So far as they go, the records exhibit more or less deficiency 
in the deposits of the Lower Lias, and the rocks do not contain rich 
faunas or earlier appearing radical species. The theory of migra- 
tion from west to east along a zone which passed to the north of 
the Alps differs from the suggestion of Mojsisovics in his work u Dol- 
omit-Riffe Sud-Tirols, etc.,” that the fauna of Central Europe may 
