146
THE ESSEX NATURALIST
one specimen taken on Baldwins Hill was of a brownish-coppery
hue.
The dorsal markings vary from slight equi-distant spotting to
liberally marked lateral lines and spots, and the ringing at the
neck (which gives it the name of Ringed Snake) will also show
marked differences, being at times almost white and at others a
pale yellow or, more rarely, a deep orange. An occasional speci-
men will lack the collar mark.
The ventral surface is always of black and white checkers in
varying patterns. Some are equally marked, others have a pre-
ponderance of either black or white; no snake is identical in this
respect and the pattern will not change throughout its life. With
the time and the equipment to photograph each specimen we
would have the equivalent of a finger-print bureau and a per-
manent record of the movements of a particular snake and its
growth year by year, providing, of course, the same snake was
caught regularly.
Dice Snake (Natrix tesselata)
During the Survey two of these snakes have been taken in the
Forest, one on Rushey Plain and the other at Goldings Hill.
Although similar in appearance to the Grass Snake, they vary
in several ways, for example, in that they are mostly fish eaters
and far more aquatic. Also the yellow collar is absent, the eyes
are set more on the top of the head and the ventral surface tends
to be of an orange colour. They are not a species native to this
country and the specimens taken were undoubtedly escapes or
releases.
Smooth Snake (Coronella austrica)
No specimens recorded.
Adder or Viper (Vipera berus)
There is little to add to the original paper.
We have found that the Adder has tended to decrease. Al-
though it is still found in its old haunts the numbers counted have
been considerably less. This is notwithstanding the hot summer
of 1959 when they produced their young a month earlier than
usual, although many of these may have been killed in the fires
of that year. We feel that the Adder is still in the Forest in fair
numbers, as during the years mentioned we have found no dead
specimens, but have added to our records by discovering them in
several places hitherto unrecorded.
That their area of movement is small is borne out by a very
large female that was collected for measuring and photographing
in April 1960. This snake was 281/2 inches long and is the largest
we have found in the Forest. She was returned to the exact place
of capture a week after she was taken and thereafter observed at
regular intervals until she hibernated in October. We returned to
the spot in March 1961 and once again we found her in the