357 



body appearing pyriform or slightly club-shaped; abdominal segments 

 with rather irregularly arranged transverse series of locomotor 

 tubercles; spiracular chamber in the form of a vertical slit. 



Pupa. — Head without projecting thorns; antennal sheath short, 

 curved downward. Prothorax about one third as long as mesothorax; 

 wings short, extending to apex of first ventral abdominal segment; 

 apices of hind tarsi slightly surpassing apices of wings. Armature 

 of dorsal abdominal segments consisting of stout thorns in a trans- 

 verse series, 2 of which, near mSiddle of segments 2 to 7, are much 

 stronger than the others ; laterad the series are discontinued some 

 distance from margins ; apical segment with 3 strong thorns on each 

 side, between which are several weaker protuberances. 



Imago. — The only species of the genus (chrysocoma Osten 

 Sacken) may be distinguished from other Tabanidae by the following 

 characters : third antennal joint consisting of 8 segments, the basal 

 one only slightly longer than the next ; fourth posterior cell open ; eyes 

 of female acutely angled above; hind tibiae with apical spurs. 



HABITS OF LARVAE) 



The eggs are usually deposited on the under side of leaves of 

 various plants, and when the larvae hatch they drop to the ground, 

 living afterwards among the decaying leaves and other vegetable 

 debris. They are very probably predaceous like other Tabanidae. 



The egg-masses are .parasitized by a proctotrypid species. 



HABITS OF IMAGO 



The female while ovipositing has the habit — which is very rare 

 among Diptera — of brooding her eggs. The species is very rare, and 

 so far as I know has never been taken in Illinois. 



For details of life-history see the papers by McAtee and by Wal- 

 ton listed at the end of the family discussion. 



Chrysops Meigen 



I have before me a number of larvae belonging to different species 

 of this genus, but only one has been definitely associated with the 

 pupal and imaginal stages. 



GENERIC CHARACTERS 



Larva (PI. LI, Fig. 1). — Spindle-shaped, very distinctly tapered 

 towards each extremitv. Head small, entirely retractile; antennae 



