— 23 — 



When the imagines of Brocheri hâve emerged from the host 

 egg, they will try to get up to the surface of the water walking 

 on the A/uphar-stalk or on the glass-side of the aquarium, and 

 they will never try to swim. When they are shaken off from 

 their substratum they will only at last wriggîe their bodies wit- 

 hout purpose and start with their legs, but no swimming motions 

 can be seen, neither with legs nor wings. 



Just as in other known parasites of submerse eggs nor Ana- 

 grus Brocheri is surrounded by any air-bubble when swimming ; 

 this is quite natura las the eggs from which they hatch hâve 

 no air-supply, and imagines met with in the water must surely 

 (most cr ail) be considered as newîy hatched spécimens on 

 passage from the hcst to the air; when catching chance spéci- 

 mens of thèse little parasites {Caraphractus, Anagrus, Prestwi- 

 chia) in open air waters I always found maies as well as females. 



2. Prestwichia aquatica LuBB. 



Within the genus Prestwichia only one species, aquatica, is 

 known. Another species, solitaria, has certainly been described 

 by RUSCHKA and THIENEMANN (1) morphologically especially cha- 

 racterized through the lacking of wings, biologically through 

 the solitary cccurrence in Odonate-eggs, while aquatica is 

 reared in numbers from its host eggs. 



The species solitaria however does not hold good, I hâve had 

 in hand a great many spécimens of Prestwichia, reared and 

 caught, and it is quite évident that ail belong to one species, 

 yet appearing in three différent fcrms : 



The typical form, which most of the former investigators 

 (Lubbock, Westwood, Enock, Willem, Rousseau, Heymons, 



RUSCHKA a. THIENEMANN, UsSING, RlMSKY-KoRSAKOw) hare had 

 in hand is characterized as follows : Female : fullwinged, black 

 brown, the hind-most part of thorax, the ovipositor, antennae 

 und legs yellow. Maie : with rudimentary wings, quite black- 

 brown. Length 0,5 — 1,3 mm. 



A variety for which I propose the name Var. hrevipennis, 

 differs from the typical form of the female having short wmgs 

 only partly covering the abdomen. This form is already men- 



ti) Zeit wiss. InsektenbioL, IX, 1913, p. 82. 



