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WESENBERG-LUND and by myself) hâve shown, in Agrion pul- 

 chellum, which thus may be regarded as the normal host of 

 subfuscus. 



Ganin (!) in his well-known paper upon the development of 

 several parasi'àc Hymenoptera has described the larval stages 

 of a « Polynema », which, according to his drawing (13-jointed 

 antennae a.o.), must belcng to the genus Anagrus. As it was 

 reared by Ganin from Agrion virgo-eggs in the underside tissue 

 of Nymphœa-leaves (i.e. from mignon pulchellum), and as I 

 hâve followed the development of the second aquatic Anagrus- 

 species viz. Brocheri and found the larval aspect of this latter 

 not to be identic with the form described by GaNIN, I feel quite 

 sure that the species of GANIN belongs to subfuscus. 



Anagrus Brocheri ScHULZ was reared by BROCHER (2) from 

 Agricnid-eggs inserted in a pièce of Phragmites found floating 

 on the water, and also from mignon pulchellum-eggs in Nym- 

 phœa-\ea.ves. 



In the peduncle cf the Brandy-bottle (Nuphar luteum) the 

 oviposition of the zygopteron Erythromma najas is often found 

 in Denmark. Thèse eggs are very often parasitized (1 parasite 

 in each egg), generally by Prestwichia, but in cne locality, 

 Funkedam at Hillerod, also by an Anagrus which is quite 

 agreeing with Brocheri, except in two characters viz. the ovi- 

 pcsitor not being darker colcred than the body, and the scutel- 

 lum being whitish ; but I do not think thèse two characters alone 

 sufficient for establishing a new species, and thus I regard my 

 spécimens as true Brocheri. 



I hâve followed the development of this species and find it 

 to be in the gênerai features agreeing with that described by 

 GANIN. For comparison, I reprint some of the figures of GaNIN 

 together with those representing the larva of Brocheri. 



Of the Ist larval stage of this latter, I hâve only seen the final 

 form having the head end lobate separated from the body 

 through a constriction (fig. 2 A) just as in GaNIN (fig. 1 C). Lengt 1 ! 

 0,18 mm. The young Histriobdellid stage (fig. 2 B) is very much 

 alike the mature larva of GaNIN (fig. 1 F), and not so much 



(1) Zeit. wiss. ZooL, XIX, 1869, p. 417. 



(2) Ann. Biol. Lac, IV, 1910, p. 177. 



