Arkell.1956.Jurassic..

SWABIAN AND FRANCONIAN ALB 119
The Macrocephalitids are even more difficult, for they require still larger
material to make subgeneric (still more specific) differences discernible.
The 'Calloviensis' Zone is stated by Kuhn (1939, p. 480) to yield M.
(Pleurocephalites) folliformis Buck, and P. lophopleurus Buck., but on plate
iii, fig. 4, what appears to be a P. folliformis is figured as M. (Kamptokephalites)
herveyi (Sow.), which if correct would imply a lower horizon,
while a M. (P.) aff. lophopleurus Buckman is figured as Kepplerites dorni
Kuhn (pi. i, fig. 12). Macrocephalites verus Buckman, the type of which
is in a 'limonitic stone' from 'the base of the Callovian' at Ehningen seems
to agree in characters and horizon best with Kuhn's 'M. aff. subcompressus
TABLE II.—SUMMARY OF THE CALLOVIAN OF THE SWABIAN AND FRANCONIAN
ALB, WITH PROVISIONAL CORRELATION NOW SUGGESTED
UPPER
CALLOVIAN
MIDDLE
CALLOVIAN
LOWER
CALLOVIAN
SWABIA AND FRANCONIA
(Model, 1935 ; Model & Kuhn, 1935 ; Kuhn, 1939)
Lamberti beds and nodules .
Athleta beds . . . . . up to 3 m.
Castor & Pollux Zone, with obductum
layer in lower part and refractus layer
at base . . . . . . 2 m.
Calloviensis & Enodatum Zone, including
the Otzing Beds, with the main Goldschnecken
fauna (Jason Zone and upper
part of Macrocephalus Zone of Reuter,
1908, 1910). Parapatoceras layer at
base, with Proplanulites spp. 4 m.
Gowerianus bed . . . . . 02 m.
Macrocephalus bed; sometimes an ironshot
marl, or a band of phosphatic
nodules . . . . . . 0-3 m.
CORRELATION
(ENGLAND)
lamberti
athleta
coronatum
jason
planicerclus
calloviense?
koenigi
kamptus
macrocephalus
Waag.' (pi. iii, fig. 2), rather than with the Calloviensis Zone specimens he
figures as M. verus (pi. iv, figs. 3, 4, pi. ix, figs. 12, 13).
Such comments could be continued at length; the specimens here
printed merely illustrate that a thorough revision of these magnificent
Callovian faunas is sorely needed.
The ammonites of the basal Macrocephalus Bed in the Swabian Alb
(for instance the Lochen district, Fischer, 1913, p. 26, and Lautlingen,
where I was shown a good temporary exposure in 1953 by Dr Holder)
are worthy of special attention. The large Macrocephalites of this bed most
resemble those in the English Upper Cornbrash and include the form which
the International Commission on Zoological Nomenclature has been
asked to fix as the type of M. macrocephalus Schloth. sp. (= M. verus
Buckman, 1922, pi. CCCXXXIV, based on an Oppel-Zittel specimen
from Ehningen), associated with Bullatimorphites (B. quenstedti Roemer
L xv
a n
sp. 1911, type Quenstedt, 1849, P > 3)> association also found in
Sicily (see p. 207). The smaller B. weigelti Kuhn sp. (1939, pi. vii, 3) is said
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