70 THE ESSEX NATURALIST
The male superficially resembles a very small example of
Enallagma cyathigerum Charp., and is not easily distinguished
from the other species of the genus Coenagrion. The markings
on the first and second segments of the abdomen of the male
provide a fairly simple method of separating the British species
and enlarged figures of these markings are given. The face is
bluish with a black area on the nose; the top of the head is
black with an oval blue spot behind each eye; the prothorax
with a sharply turned down projection to central lobe; the
Dorsal views of the first two abdominal segments of Enallagma
and Coenagrion (much enlarged).
1. E. cyathigerum. 4. C. mercuriale.
2. C. puella. 5. C. hastulatum.
3. C. pulchellum. 6. C. scitulum.
C. armatum is not shown as it differs so greatly from the other
members of the genus that confusion is impossible.
thorax black with two narrow blue stripes on the dorsal surface,
sides blue shading to pale green; the abdomen cerulean blue
with a distinctive black mark on the dorsal surface of the second
segment. This mark resembles a short U with a thick base,
joined by a fine stem to a posterior black marginal ring-; this
stem may be absent as in the specimen taken by Mr. Hammond,
or the arms of the U may be so shortened that the marking
resembles that of E. cyathigerum as in the case of the other Essex
specimen. From this it will be seen that a typical male scitulum
has not yet been seen in this country. The remaining segments