176 ENTOMOLOGY 
triungulin larvee issuing from a female Stylops in the body of 
an Andrena. The further life history of Stylops is but 1m- 
perfectly known; probably the triungulin climbs upon a bee 
or a wasp and enters its body, after the manner of the Euro- 
pean Rhipiphorus paradoxus, whose life-history is much bet- 
ter understood. 
The most extraordinary metamorphoses have been found 
among parasitic Hymenoptera, as in Platygaster, a proctotry- 
pid which infests the larva of Cecidomyia. The egg of Platy- 
gaster, according to Ganin, hatches into a larva of bizarre 
Stages in the hypermetamorphosis of Platygaster. A, first larva; B, second larva; 
C, third larva; a, antenna; b, brain; f, fat-tissue; h, hind intestine; m, mandible; mo, 
mouth; ms, muscle; nm, nerve cord; r, reproductive organ of one side; s, salivary 
gland; t, trachea.—After GANIN, 
form (Fig. 218, 4), suggesting the crustacean Cyclops, rather 
than an insect. This first larva has a blind food canal and no 
nervous, circulatory or respiratory systems. After a moult 
the outline is oval (B), and there are no appendages as yet, 
though the nervous system is partially developed. Another 
moult, and the third larva appears (C), elliptical in contour, 
externally segmented, with tracheze and a pair of mandibles. 
