Arkell.1956.Jurassic..

TITHONIAN
BALUCHISTAN 397
On the Windar River, Las Bela State, Dr W. L. F. Nuttall in 1924
collected fragments of Virgatosphinctes denseplicatus (Waagen) and V.
cf. subquadratus Uhlig (now in the Sedgwick Museum, Nos. F778-781
and F782-3).
LOWER CALLOVIAN
Mazar Drik Limestone (Mari Hills): alternations of rather thin-bedded
limestones and shales, containing ammonites of the Macrocephalus Zone
of Cutch, monographed and correctly dated by Noetling (1897) and
revised by Spath (1933, p. 808). Macrocephalites, Dolikephalites, Indocephalites
and Pleurocephalites spp., with Indosphinctes aff. errans Spath
and Choffatia aff. recuperoi (Gemm.). Large Indocephalites were mistaken
by Noetling for the similar Epimayaites polyphemus (Waagen), which,
however, is of Upper Oxfordian date. The original name of Polyphemus
Limestone for this group has therefore had to be changed (Arkell, 1951,
Mon. English Bathonian Am., Pal. Soc, p. 36).
UPPER BATHONIAN
Mazar Drik Limestone (presumably lower part). Noetling on his
pi. vi figured two typically Upper Bathonian ammonites, Bullatimorphites
bullatus (d'Orbigny), which he correctly identified and recognized as pre-
Callovian, and a 'Harpoceras' which Spath (1933, p. 808, and pi. cxxx,
fig. 3) renamed 'Oppelia baluchistanensis', but which is an Upper Bathonian
Clydoniceras. Some of Noetling's Chqffatiae also resemble Bathonian
forms more closely than Callovian. It would therefore appear that, like
the English Cornbrash and the condensed limestone of Mount Strunga in
Rumania, the Mazar Drik Limestone bridges the Upper Bathonian and
Lower Callovian (Arkell, 1951, loc. cit., p. 36). It will be interesting to
see whether more careful collecting in the future proves the two faunas
to be distinct stratigraphically as in the Cornbrash.
'MIDDLE JURASSIC'
'Massive grey limestones several thousand feet thick' (Vredenburg, 1909,
p. 200). No ammonites known.
'LIAS'
'Dark-grey, almost black, regularly stratified limestones, several thousand
feet thick, sometimes interbedded with richly fossiliferous dark calcareous
shales' (Vredenburg, 1909, p. 200). Within this series the following
ammonite faunas have so far been recognized.
LOWER TOARCIAN
Black shales near Kelat and on the Natrani River, Las Bela, have
yielded an abundant well-preserved ammonite fauna of the Italian Lower
Toarcian, including various species of Phylloceras, Juraphyllites, Lytoceras,
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