D. Iveilin 
445 
tain of Trafalgar Square (London). The larvae attack chiefly the young snails, 
which, when parasitised, usually leave the water. The author was not sure as 
to the real necessity of the Mollusc for the development of this Chironomid. 
This case of parasitism needs verification and more attention ought to be paid 
to the feeding habits of the larva and to its close relation to the host. 
Melinda cognata Meigen.: the larvae live as parasites on Patula rotundata 
Muller and Helicella virgata da Costa. For the complete life-cycle of this fly 
see the first part of this paper. 
Melinda sp., probably Melinda gentilis, is a parasite of II. virgata (see 
p. 442 of this paper). 
Melanophora helicivora Goureau. Goureau (1843) obtained six specimens 
of this fly from seven specimens of Helix consy areata, which he collected 
in Paris and enclosed in a paper cone. He concluded that the fly lays one egg 
in each shell, and that the larva which hatches from the egg devours the 
Mollusc and transforms itself into a pupa inside the shell of the host; the 
adult fly emerges in autumn. Goureau’s observation, as I have already men¬ 
tioned (1915a), is very incomplete and this case of parasitism also needs 
further verification. 
I 
It is somewhat interesting to mention here that the other species of this 
genus: Melanoyhora roralis L. was obtained by Heylaertes from Asoyia 
farinalis (recorded by Van der Wulp 1869, pp. 184-185). Brues (1903), on the 
other hand, found the pupae of this species in an empty skin of Porcellio 
(terrestrial Isopod). 
Some unidentified Dipterous larvae, living as parasites upon Molluscs, 
were recently recorded by Schmitz (1917). In two cases he found them in an 
Avion collected near Sittard, Holland, and in one case in a Helix asyersa L. 
collected in Luxemburg. 
(2) Carnivorous Forms. 
Mydaea sp. allied to Mydaea bivittata Macq. In a recent paper by Rodhain 
and Bequaert (1916, p. 248) we find the following observation on the feeding 
habit of the larvae of this Anthomyid: 
“The genus Mydaea exists in central Africa and its larvae are carnivorous; 
one of us bred at Kivou a great number of a species allied to M. bivittata Macq. 
(identified by Dr Villeneuve) from the larvae devouring a big terrestrial 
Mollusc ( Burtoa nilotica Pfeiff.).” 
I would note that the larvae of the other species of this genus ( Mydaea 
ancilla Meig., vrbana Meig. and very likely tincta Zett. and yertusa Meig.) 
are either carnivorous, living upon the larvae of other Insects, or (Mydaea 
yici Macq., anomala Yaenn., torquans Nielsen and syerwoyhila Townsend) pro¬ 
ducing subcutaneous myiasis in different birds. 
