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

HIMALAYITES. 137
Besides Oppel's type specimen we place here two specimens from Lochambel-
kichak which differ in some subordinate characters from the type, but not to
such an extent that they could be looked upon as distinct species. We muHt,
however, keep in view the possibility of a richer and better preserved material
supplying us with new and distinct characters which may necessitate the separa-
tion of these forms as good species. The last volution of the specimen depicted
in figure 1 of plate 39 is exactly as high as broad ; the specimen is consequently
somewhat flatter than Oppel's type. Further, the intercalated ribs run a some-
what less straight course and show a certain tendency towards uniting with
neighbouring tubercles or at least towards approaching the latter. As far as
can be made out, the lobes are copiously branched. The second specimen (plate
XL, fig. 1 a—d) approaches the type by reason of its greater thickness, but
differs owing to the ribs being more densely crowded and the cross-section ap-
parently more rectangular. This rectangular form of the cross-section comes,
however, into evidence only where the left flank shows signs of being injured
so that the discrepancy in the shape of the cross-section as well as the flatten-
ing of the left flank are most probably to be ascribed to the injury referred to.
Closest allied to H. Seideli are H. kulianus, H. Schlagintweiti and H. Stolicz-
kai. The distinguishing characters are enumerated in the descriptions of these
species. A striking resemblance to Himalayites Seideli is exhibited by Reineckia
Brancoi Steinmann from the Callovian of Caracoles. As far as can be judged
from the figure of R. Brancoi, the broad ventral furrow and the less frequent
appearance of intermediate ribs in R. Brancoi are the only characters which
render possible a discrimination of the latter species from H. Seideli. But it
is very probable that differences exist in the structure of the suture and the
development of the inner volutions, differences the significance of which it is at
present impossible to gauge, since Reineckia Brancoi is not sufficiently well known
in those respects.
As already noticed by Steuer, the characters of H. Seideli taken in their
totality recall Reineckia egregia Steuer from the Tithonian of Argentine. The
absence of intermediate ribs, the presence of isolated umbilical tubercles and
the greater number of tubercles on the flanks of Reineckia egregia render its
^diMjfii^inatipn fron^. Seideli an easy task. Whether Ammonites egregius has
^^FpToper'plac^Himalayites cannot be determined with certairty.
specimens from Spiti under Ammonites Seideli, but in
reality only two appear to belong theie. Two specimens are from Lochambel-
kichak (Coll. Diener-Griesbach).
V
/ . HIMALAYITES KUTIANUS.N. sp.
Of this species, which is closely related to H. Seideli Oppel, yet specifically
distinct from it, only a fragment is at our disposal. But exhibiting, as it does,
o