DESCRIPTION OE PLATE A. 
95 
DESCRIPTION OF PLATE A. 
Fig. 1. — Head and rostrum of Sipliono^hora circum- 
flexa, showing s, the three stemmata ; e the com- 
pound eyes ; o o, the superposed ocelli ; clypeus ; I, 
labrum ; rostral joints ; v, vertex; 
Fig. 2.- — Side view of Siphonojohora rosce. c, coxa ; 
/, frontal tubercles ; connecting membranes ; Z, 
labrum covering the rostral groove. 
Fig. 3. — Second, third, and part of the first rostral 
joints of the same. &, protruding set^. The second 
joint is perforated, not channelled like the others. 
Fig. 4. — Part of the third antennal joint of the male 
of Phorodon galeopsidis. t, tubercles ; m, membranes 
distended or stretched over the irregular ringed 
apertures. 
Fig. 5. — Sixth, seventh, and part of the fifth 
antennal joint of the same. 
Fig. 6. — Apical portion of the seventh joint. 
Fig. 7. — Fourth, fifth, sixth, sevqnth, and part of 
the third joints of ScJiizoneura Ulmi. This figure and 
Fig. 5 show the pseudo-articulations of the sixth and 
seventh joints. By most authors they are recognised 
as separate joints. 
Figs. 8, 9, and 13. — Portions of the leg of Aphis 
pruni. /, femur ; Z, tibia ; r, tarsus ; Uj claws ; 
pulvillus, with its contractile ligament; r and flexor 
and extensor muscles ; m, membrane connecting tarsus 
with process of the tibia. 
Fig. 10. — Tarsus of Myzus persicm, showing the 
membrane when the tarsus is extended. 
Fig. 11. — Tarsus of Aphis rumicis, showing the 
membrane when the tarsus is contracted. 
Fig. 12. — Knee of Siphonophora toscb^ showing s, the 
dilating circulatory sac, which pulsates from 120 to 
180 times in a minute. The expansions of this sac 
