— Without ventral spine on segment 8 ...................................... 24
24 Abdomen blue with black arrow-shaped
markings as in blue form of E.
cyathigerum female (check site for more
distinctive males).
(Believed extinct in Britain) Coenagrion scitulum
female
(Dainty Damselfly)
— Green or blue with black markings which
are not shaped as above. ...................................... 25
25 Posterior margin of prothorax gently
curved.
'Thistle-shaped marking on segment 2 of
abdomen.
Other segments mainly black on green or
blue background. Where black markings
are reduced in size, blue- and-black
patterning is as shown. Coenagrion puella
female
(Azure Damselfly)
— Posterior margin of prothorax deeply
indented.
'Mercury'-shaped marking on segment 2
of the abdomen.
Other segments with blue-and-black
patterning as shown for C. puella. (Note:
there is an uncommon blue form of C.
puella which also has the mercury' mark
on segment 2. Always check shape of
prothorax and confirm by observing
males if possible.) (Extremely rare in
Essex).
122