30 THE ENTOMOLOGIST. 



species which had oviposited early in the year before the drying 

 up of the ponds and smaller streams. Information is unfortun- 

 ately scanty with regard to such periods of drought, but what 

 little there is seems to point to the fact that they have but slight 

 harmful effect on odonate existence. The eggs probably remain 

 imbedded in the mud, where sufficient moisture remains to keep 

 alive the little speck of protoplasm, and it is not too much to 

 suppose that the nymphs may maintain their existence under 

 the same conditions. In this connection Mr. McLachlan's ob- 

 servation of Agrion mercuriale, ovipositing in mud in Savoy in 

 1884 (Ent. Mo. Mag. 1885, p. 211), and of Pyrrhosoma minium 

 doing the same in the New Forest in 1895 (Ent. Mo. Mag. 1895, 

 p. 180), are most useful. My own observation duriug last autumn 

 of the eggs and freshly hatched larvae of Sympetrum vulgatum 

 tend to shew their hardiness. For, about the 15th of September 

 last a female laid in a collecting-box a large number of eggs 

 (some two or three hundred perhaps), which were elliptical in 

 section, the major axis being about | mm. On reaching home 

 I placed them in water, and about a month later the young 

 larvae commenced hatching out, and others continued to appear 

 for a month or so longer. Though many of them were hatched 

 in a porcelain evaporating dish about four inches in diameter, 

 and could have had practically no food for weeks, their vitality 

 did not seem to be impaired, and few, if any, died. They have 

 now been removed to better quarters, where they may perhaps 

 thrive, in which case some of them, in three years or so, may 

 produce imagines in spite of their early fast ; for dragonfly 

 nymphs do not seem to sustain any permanent harm from being 

 kept for weeks without food in the smallest quantity of water and 

 that of a very stagnant nature. 



It is in connection with the immature state of these insects 

 that the odonatist has most opportunities of opening new ground, 

 and it is a distinct advantage that he is able to carry on his 

 observations and do most useful work during the winter and 

 early spring. Of course some kind of vivaria will be required to 

 contain the nymphs that are being bred. Mine consist of glass 

 fish-globes filled with uater, mud, and weeds, with a few sticks 

 or reeds projecting about a foot above the surface of the water, so 

 that no misfortune may happen when the time for the emergence 

 of the dragonflies arrives. In these, last year, I reared JEschna 

 cyanca, Agrion piiclla, Ischnura elegans, PyrrJiosonia miniiim, and 

 Erythromma najas, the last two of which I have described and 

 figured. 



Nymph br Pyrkhosoma minium, Harr. (fig. 1). — lu shape it is long 

 and slender, though less so than some others of the Agrionidcn: length, 

 including the caudal lamellae, 19 mm., greatest breadth about 2-5 mm. : 

 general ground colour dark sepia-brown. The head is somewhat 

 rectangular, about 3-25 mm. by 1-75 mm. ; tbe sides, however, slope 



