ODONATA IN GERMANY. 119 



The habits of the female when ovipositing are also interesting. 

 At about a yard from the bank she may be seen dipping the tip 

 of her abdomen quickly and at random into the water, flying 

 onwards all the while. After a time she will fly out over the 

 water, probably followed by several males, one of which will 

 copulate with her, and both will fly back to settle on the bank ; 

 having rested there awhile, both fly over the water, and the 

 female breaking loose again begins ovipositing. I watched the 

 same female do this repeatedly, and the process of oviposition 

 seems to point to the fact that, in this dragonfly, different 

 batches of eggs are fertilized separately. The female emerges 

 about a week before the male. The females which I took in 

 August perhaps had a trace of blue powder on the abdomen. 



I observed the insect for the last time on August 27th. In 

 July there were a few specimens in the brickyard, but the species 

 was most plentiful at the pond adjoining the Lahn. 



Cordulia cenea, Linn. — The first dragonfly I came across in 

 Marburg was an immature female of this species ; it was picked 

 up in the town on May 12th and brought to me. On May 23rd 

 it was out in some numbers along the banks of the Lahn towards 

 Giessen, but on May 25th there were none to be seen in this 

 locality. I next observed the species on June 9th at the pond 

 adjoining the Lahn, and after this it was plentiful until August 

 3rd, after which date I did not observe it. From the brickyard 

 and the marsh I did not record it. It was also plentiful along 

 the banks of the Lahn in June, and at a small pond in the 

 Marburg botanical gardens, which, by the way, are situated in 

 the heart of the town. The habit of this species is to fly back- 

 wards and forwards along the edges of ponds, seldom settling 

 under the banks. It is very wary and difficult to net. Once or 

 twice I saw specimens settle in the grass; and on one occasion I 

 found a male resting on a dead twig. 



The female oviposits in the shallow water among reeds by 

 dropping the eggs quite at random. When thus engaged the 

 insect is by no means shy. 



Somatochlora metallica, Van der L. — On August 3rd I noticed 

 a dragonfly ovipositing in the thick reeds by the side of the pond 

 near the Southern Eailway Station. At first I thought it was 

 Cordulia anea, but when I tried to net it, it at once flew up and 

 settled among the branches of a plum-tree close by. Thinking 

 this very peculiar for a female C. cenea to do, I followed and 

 drove the insect back to the water, where I captured it, and 

 found it to be a fine female of S. metallica. 



Ovipositing is much the same as that of the last species. 



I did not come across the dragonfly again. 



Gomphus vulgatissimim, Linn. — While boating on the river 

 Lahn on May 15th, I found an empty nymph-case clinging to a 

 leaf on the bank. 



