136 
Psyche 
[June 
inal air layer is visible in living specimens of the latter (Parsons 
1970). The third abdominal spiracles (Figs. 5-7, S3) and the spira- 
cles posterior to them are located among the hairs in all three in- 
sects. In Diaprepocoris (Fig. 5) a longitudinal sulcus lies medial 
to these spiracles on the third through seventh abdominal segments. 
Micronecta, unlike the other two insects, possesses short hairs 
as well as long ones on the ventral abdominal surface. The short 
hairs are more sparsely distributed medially than laterally, and 
on the fifth and more posterior abdominal segments they end ap- 
proximately 10 pm from the lateral edge of the body, which is 
devoid of hairs. Leong (1961) mentioned the presence of “fine 
hairs” and a silvery ventral air layer on the abdomen of Micro- 
necta sp. 
Fig. 5. D. zealandiae, ventral view. Head and legs removed; coxae and long 
setae shown only on right side of figure. Mesothoracic spiracle (S II) concealed by 
prothorax. 
