BRITISH ODONATA IN 1913. 81 
It should be stated that the aquarium in which the 1912 
nymphs wére bred was standing on a brick window-sill, where 
the window was open day and night all through the winter. The 
weather being mild the water did not freeze, though it did in 
former years. In fact a nymph of a larger species was on one 
occasion frozen in the middle of a solid piece of ice and 
remained so for two days. When the thaw came it revived and 
seemed none the worse. These nymphs were not forced, there- 
fore, by unusual heat, but probably were by receiving an 
unnatural amount of food. As soon as they began to eat 
Chironomus larve, they were fed almost daily and when nearly 
full-grown would sometimes eat as many as eight in succession, 
though each was as long as the nymph itself. Probably in 
confinement space has something to do with the rate of growth. 
For a few kept in a very small bottle with abundance of food 
scarcely grew at all, and when they were moved into a larger 
aquarium, where food must have been more difficult to procure, 
because less plentiful, they were found to be scarcely more than 
half the size of some which had already been there for six weeks. 
All emerged in the early morning, usually on dull days. One 
nymph showed a particular aversion to sunshine. Being ready 
to emerge, it crawled out of the water ona cloudy morning. 
When on the wood the sun came out rather suddenly, and the 
nymph immediately scrambled and fell down. As soon as the 
sun disappeared it climbed up again; but on the sun’s reappear- 
ance it repeated its previous performance. It did this three 
times, and the nymph was not contented till the aquarium was 
shaded, when it emerged none the worse for what had happened. 
Miss Molesworth’s interesting notes may suitably be supple- 
mented by a description* and figure (Plate II.) of a full-grown 
nymph of S. striolatum, which I have therefore prepared :— 
Description.—General colowr sepia, from very pale to quite dark. 
Length, including anal appendages, about 18 mm.; greatest breadth, 
about 7mm. Head of moderate size; in outline a flattened pentagon ; 
width about 5°56 mm. Antenne of seven segments, the basal two 
short and rather swollen, the rest more slender, with a ringed appear- 
ance. Mask (labium) tapering backwards to the middle hinge where 
it is narrow; this hinge’ almost as far back as the insertion of the 
midlegs; extremity spoon-shaped, covering the face; palpi broad, 
where they approach one another and there serrated ; teeth reddish ; 
movable hooks, long, sharp, slender; centre of Sabium produced in 
an obtuse angle; on this lobe, internally, are two semicircles of long 
reddish hairs, about fourteen in each, the lateral margin of each 
palpus fringed with a similar row of hairs, pointing inwards. Several 
pale marks in front of vertex, which also has pale markings. Hyes 
* A figure of S. vulgatum (= striolatwm) in W. H. Nunny’s paper, 
‘Science Gossip,’ July, 1894, does not appear to represent a Sympetrum at 
all, and is certainly not S. striolatum. 
