ialontolngia ndita,

FAUNA OF KACHH (CUTCH).
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Reineckeia and forms described by other authors (e.g., Ne-uqueniceras bodenbenderi
Tornquist sp.) are intermediate, and whilst tuberculation appeared only
on the outer whorls of Ne-uq-ueniceras, it may have arisen first on the inner
in some Reineckeia, without having been preceded by a costate stage. If
· we assume derivation from a Stephanoceratid ancestor for the one and
from a Perisphinctid for the other, the essential uniformity of the South
American assemblage is perhaps more difficult to explain, although they are
all Stephanoceras derivatives. But similar homreomorphs are still developed in
the Uppermost Jurassic (Himalayites, ex Aulacosphinctes) and these also are
so closely allied that we cannot go back to Reineckeia for the ancestry of one
and to quite a different source for another type closely connected with the
first by numerous transitions.
Again, it may be remembered that the Perisphinctoid stock to which
belong Siemiradzkia and Grossouvria produced N euq-ueniceras-like offshoots once
more at a late date, i.e. Subgrosso-uvria Spath, and PseudopPltoceras, gen.
nov. (for Amm. chauvinianus d'Orbigny, 1846, pl. · CLXV). According to unfigured
Scarborough and Montreuil-Bellay (Maine et Loire) species in the B.
M. (Nos. 39312=Amm. famulus, Bean MS and C. 14733) this develops inflated
N euqueniceras-like body-chambers, with constricted apertures, entirely different
from the true Peltoceras of the athleta group, although it may convemently
be grouped in Peltoceratidre.
The genus Reineckeia, Bayle, is abundantly represented in Kachh, although
mostly by fragments.
Bayle (1878, pl. LVI, figs. 1-3) figured three species of Reineckeia which
are genosyntypes. The lectotype is his Reineckeia anceps of fig. 1, which
differs in size from Reinecke's type (1818, p. 82, pl. VII, fig. 61), but has
been included with it by Petitclerc (1915, p. 90) and Loczy (1915, p. 358)
and doubtfully by Parona and Bonarelli _(1897, p. 160). The small Franconian
form, a typical Uetzing example of which is here figured (pl. XLIV, figs.
6a-c) is characterised by its cadicone whorl-shape ; in the larger specimens
figured by Bayle and d'Orbigny (1846, pl. CLXVII), renamed R. substeinmanni
. Lemoine (1910, p. ), the resemblance may be slight in the drawings, however
beautiful, but a typical Sarthe example of Bayle's form (B. M. No. C. 26248)
has cadicone inner whorls that could not be distinguished from the true R.
anceps. Moreover, one of many Uetzing examples in the British Museuin is
still septate at 40mm. diameter so that even size is not a distinguishing feature.
Like other highly ornamented ammonites, the forms of Reineckeia show
an astonishing variability and no two examples are probably identical in all
details. Thus we. have in this genus a large number of (unnecessary) species
often based on single specimens whilst in the contemporary unornamented
Phylloceratids there are only few species but many individuals of each.
To the typical anceps group of Reineckeia 1 belongs the Kachh · R. arlhritica
(Sowerby) and seven allied species 1 whilst for some less tuberculate forms,
1 A number of new Mexica.n species ha'\"e lately been described by Burckhardt (1927), but his important memoir
arrived aft.flr this part was in page proof.
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