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96 GENESIS OF THE ARIETIDA. 
by very few forms in the basin of the Rhone, and Ver. spiratissomum appeared first 
in the Lower Bucklandi bed. 
In England the number of varieties or forms is not equal to either of the 
three faunas above mentioned, but the transitional forms are present. Wright, in 
his “Lias Ammonites,” gives a section at Red Car, and Amm. Conybeart is cited as 
occurring in the lowest stratum of the Bucklandi zone. With regard to the Eng- 
lish fauna, one can see, in spite of the large size and the multitude of speci- 
mens, that the small number of distinct species and the entire want of autoch- 
thonous species, or varieties, indicate a purely residual fauna composed of un- 
modified forms. This basin is north of the zone in which autochthones arose 
during the Lower Lias, and the basin of the Rhone lies south of this zone, and 
both are residual faunas. Ver. Conybeari is mentioned by several authors as 
occurring in North Germany and in Luxemburg, but, so far as we have seen, 
other forms of this genus have not been cited, and Vermiceras appears to have 
had but slight development in these basins 
The facts, so far as now known, are opposed to the inference that this series 
originated in the Northeastern Alps. On the contrary, it seems more likely 
that it began in the Caloceras bed of South Germany with a variety of Cal. 
Jaqueum, and subsequently appeared as Ver. prespiratissimum in the fauna of the 
Angulatus zone in the Mediterranean province. The series, however, did not, 
either at this time or on any subsequent horizon in this province, meet with 
very favorable conditions for the evolution of new forms. It must be remarked, 
also, that the variety of Conybeari figured by Hauer and by Herbich has a whorl 
quite distinct from that which occurs most commonly in Central Europe. It is 
more like the degenerate variety of Conybeari, which is usually called Bonnard, 
though apparently of smaller size. 
ARNIOCERAS. 
There are quite a number of forms described by various authors as having 
been found in the Mediterranean province, but they have all been found in hori- 
zons above the Lower Bucklandi bed. This may be seen by our Table VI, 
and also in the fact that Suess and Mojsisovics found no species of this genus in 
the Osterhornes mountains, the beds above the Bucklandi zone being unfossil- 
iferous, and Paul states, in his article “ Die Nérdliche Arva,’? that only one 
species of this series was found in the Lias, and this occurred in the beds above 
the Bucklandi zone. 
My notes on the collections at Stuttgardt and Tiibingen do not show so rich 
a fauna as in the Cote d’Or, nor do Quenstedt’s publications indicate so full a 
development of the series as in that basin. Thus, though the series began in 
the Angulatus zone, as shown in Fraas’s collection, it did not reach its acme of 
development in the South German basin. The evolution of Arnioceras in the 
fauna of the Cote d’Or is exhibited in the Semur collection, and in Boucault’s col- 
lection of the Museum of Comparative Zéology. The large number of forms in 
1 Jahrb. geol. Reichsans., XVIII., 1868, p. 233. 
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