253 
M. anomala the frons is a little narrower, and the reddish frontal 
triangle disappears upwards, while in M. torquans the latter is fairly 
distinct up to the vertex; in the female the frons is considerably 
narrower than in M. torgquans, and the middle stripe not broader than 
the sides; the sides and the cheeks are yellow in M. anomala and 
silvery in MM. torquans; finally the female of M. anomala has the 
legs coloured like the male, while in M. torquans they are darker. 
Besides this there is also a biological difference between the 
two species. As above mentioned Mr. Mogensen has based his 
Opinion of the. distinctness of MM. anomala upon the fact, that the 
larva produces a cocoon, and he has told me, that he never 
observed such cocoons by his breedings of M. torquans. After this 
We can admit, that the last named species pupates without cocoon. 
In my previous paper I have mentioned a few literary records of 
dipterous larvæ parasitic on birds. Among these there are two") 
in which the authors record the cocoon making habits of the larva 
of Aricia pici Macq.?). Also Aug. Busck?) mentions that Mydæa 
pici Macq. pupates in a cocoon of particles of earth glued together 
by a glistening white excretion, while Townsend") in a paper 
containing the description of Mydæa spermophilæ n. sp. does not 
mention a Cocoon. As it is possible that there are more Mydæa 
species of parasitic habits I shall not make any attempt at identifying 
the flies mentioned by the said authors with my two species as 
I have not had the opportunity of seing the type specimens. 
i. Macquard: Notice sur une nouvelle er d'Aricia (Ann. d. la Soc. 
entom. de France 3. Série I. 1858. p. 655). 
R. Blanchard: Contributions å nr des Diptéres parasites. Troi- 
siéme série. (Ibid. LXV 1896 p. 652). 
?”) After the determination of the lat e Prof. Brauer the fly which has 
formed the object of the ørerne of Prof. hor røg is rr 
with M. anomala Jaenn.; it is sure that Aricia pici Macq. is a My- 
dæa, but the species is not recognizable atter mt teltoldon åkd the 
figure of Macquard. 
”) Aug. Busck: Bid pici Macq. (Pros. Entomol. Soc. Washington 
VIII. 1906 
ORE malle in Transacts. Amer. Entom. Soc. XXII 1895 p. 79 
