Ser. XV. HIMALAYAN FOSSILS, Vol. IV. THE FAUNA OF THE SPITI ...

HOPLITES. Jtf!
Considering the deficient state of material at our disposal, it is impossible
to arrive at any final conclusion with regard to the points in question, and
the definition of Leopoldia must be taken as somewhat provisional Neverthe-
less, from the systematic point of view, the advantage gained by uniting these
forms into one group is sufficiently obvious to justify the creation of a new
generic term.
By placing Leopoldia Leopoldi together with Leopoldia gibbosa and Leo-
poldia Leenhardti (H. neocomiensis Pictet et Camp.) we differ from Pictet who
connects Hoplites Leopoldi with Hoplites radiatus and even considers that the
two forms may be specifically identical. 1 According to Pictet and Campiche
the earlier stages of the two species are scarcely distinct from each other. This
statement, however, does not agree with other experiences. Acanthodiscus radia-
tus from Northern Germany and Acanthodiscus subradiatus from the Spiti ShaleB
as well as the species most closely allied to them do not show the least relation
to Leopoldia Leopoldi. The suture-lines are totally different and, as has beeD
observed in Acanthodiscus subradiatus as well as in Acanthodiscus radiatus, their
innermost whorls exhibit even at the earliest stage the typical Acanthodiscus
sculpture. We find it therefore impossible to connect these forms with Leopoldia
Leopoldi. It is not impossible that the observations of Pictet and Campiche
refer really to a form not identical with, but related to, Leopoldia Leopoldi, a
form which shows a tendency towards the formation of tubercles and bears a
certain external resemblance to Hoplites radiatus.
Another means of conciliating these contradictory views can be found in
A. v. Koenen's conjecture that Pictet's Ammonites Leopoldi is really not the
same species as d'Orbigny's, but a species with normal lobes, named Hoplites
Kiliani by A. v. Koenen. 2 A solution of this difficulty by a study of Pictet's
original specimens is very desirable.
HI.—THE SPECIES OF HOPLITES FROM THE APTIAN AND THE GAULT.
The poverty of the Upper Neocomian in forms of Hoplites renders it extremely
difficult to arrive at any satisfactory conclusion with regard to the connection
between the species of Hoplites from the Aptian and the Gault and those from
the Neocomian. The isolated form from the Barremian, such as Hoplites Feraudi
d'Orb., H. Soulieri Math., H. cruasensis Torcapel, are probably connected with
the Neocomian Hoplites. A number of other species, originally referred to Hop-
lites or else to Acanthoceras, have been united by D. Anthula 3 with certain tufcer-
culiferous forms and raised to the dignity of a genus Parahopliies. This group
also is probably a branch of the Hoplites stock and this is probably the
1 Ste-Croix, p. 243.
2 Ammonitiden des norddeutschen Neokoms, p. 1(38. Baumberger (Abh. der Schtceiz. pal Ges., ToL XXXTT.
1905) has observed Hoplites Kiliani at Ste-Croix, and classified this species as o member of the genu Leo-
poldia. [E. V.]
a Kreidefossilien des Kaukasns. Beilrage zur Paldontologie'Oesterreich- Vngams, XII, 109.
H