106 GENESIS OF THE ARIETIDA. 
lowest beds and in the Bucklandi zone, but is deficient above. Asteroceras is 
probably more fully represented than is shown in the table, since the extremes 
of the series have been found, and, the fauna being near to that of the Cote 
dOr, there are grounds for anticipating the discovery of intermediate forms. 
Agassiceras is complete in its lower forms, but Scipion’s has not yet been found. 
The oxynoticeran series is not only quite complete, but has also a middle lias 
representative. As regards Schlotheimia, Caloceras, Vermiceras, Arnioceras, and 
Asteroceras, this fauna impresses one as containing the most highly modified 
derivatives, and as being possibly a residual fauna representing an acme of choro- 
logical migration and varietal modification so far as these genera are concerned. 
Possibly Oxynoticeras will also have to be included in this category, and then the 
parallel with the English fauna north of what we have called the zone of 
the autochthones would be complete. 
Fauna or EnGianp.— Tasie LV. 
In this table the same regularity of succession is found in the schlotheimian 
series as in the Cote d’Or and Rhone basins. Caloceras is again deficient in the 
Bucklandi zone, as in the Rhone basin, but is quite fully represented and has an 
extraordinary new form in the Raricostatus bed, Cal. aplanatum. There is also a 
curious parallelism with the Rhone fauna in the arnioceran series, which, as in 
that basin, has the extraordinary form of Arn, Macdonelli of the Raricostatus bed. 
Besides the general absence of radical species, except of course the generally 
distributed psiloceran and caloceran radicals, there is in this fauna a very impor- 
tant fact to be noted, similar to that observed in the fauna of the Rhone. The 
extreme modifications in the highest formations are very generally present, — 
more so than in any other fauna. Thus, besides Cu/. aplanatum and Arn. Mac- 
donelli there are doubtful forms of Cor. bisuleatum in the Oxynotus zone.  As?. 
Collenoti, Ast. denotatum, and the extraordinary series of var. sagillarius of Ast. 
obtusum, are also present. The Oxynotum subseries is complete, and the second 
or Guibalianus subseries alone is imperfectly represented. 
The English fauna is therefore a residual fauna, not only because of the 
absence of radicals, but because it presents a chronological and biological acme in 
the evolution of the most highly modified and most recent forms of the different 
series, thus clearly indicating chronologically and biologically its more recent 
derivation by chorological migration from the older, though apparently contem- 
poraneous, faunas of the autochthonous zone. 
Fauna OF THE Province or CentTRAL Evrorre.— Taser V. 
This table has already been amply explained, with the exception of certain 
general facts. The independent origin of the schlotheimian and psiloceran series 
is in strong contrast with the Northeastern Alps fauna, which as tabulated in 
Table VI. shows that Psiloceras and Schlotheimia are connected by means of 
intermediate weehneroceran forms. Schlotheimia and Caloceras are character- 
