236 THE TWO FORMS OF THE SEA-ASTER.
the other two species occurring but very rarely. In this con-
nection it is of interest to note that in the case of Ilford the
remains of the prevalent species of Rhinoceros exhibit a tendency
to vary towards the prevalent species occurring at Grays
Thurrock in the greater complication of the transverse valley of
the molars by combing plates—a character much more common
in R. leptorhinus (the Grays form) than in R. hemitoechus. A
precisely analogous instance is presented in the relationship
between the Elephant remains found in the deposits of the
two localities. At Ilford Elephas primigenius is the common
form, while at Grays Thurrock this position is held by
E. antiquus. But many of the molars from Ilford of the
Mammoth depart from the typical form of that species and by
having plates of thicker enamel, more or less complicated by
crimping, they approach in appearance what is seen in
E. antiquus.
In the present state of our knowledge, no conclusions can
be with safety drawn from these facts of distribution. They, in
common with many other ascertained facts of Pleistocene
Geology and Palaeontology, indicate important portions of the
history of the Thames Valley, but these portions we cannot read
until we have been able to appreciate many factors which as yet
are but little understood.
In conclusion I have to express my best thanks to the
gentlemen mentioned in this paper for the loan of their speci-
mens and my warmest gratitude to Mr. F. W. Reader for his
kindness in preparing the admirable figures in the accompanying
plate.
THE TWO FORMS OF THE SEA-ASTER
(ASTER TRIPOLIUM;.
By PERCY CLARK, B.A.
As I now write (September 6th, 1901) the Essex Salt-
marshes, bordering the sea, which are overflowed by the water
at springtides, present a beautiful appearance. The tall up-
standing masses of the Sea-Aster growing there in wild and
unchecked profusion, are all in flower, and their small golden
heads massed together in thousands shed a glow of soft yellow
colour over the Saltings. But a few paces inland where the