158 
Psyche 
[June 
AC2 MM S2 P MP PNIH 
Fig. 23. M. sedula; semi-diagrammatic lateral view of thoracico-abdominal 
region, prepared as in Fig. 21. Heavy black dot indicates position of coxal process; 
heavy dotted line indicates dorsal edge of inner wall of metathoracic epimeral lobe 
(EML). Head of arrows indicates position of first abdominal spiracle (removed) 
in thoracico-abdominal membrane (TAM); spiracle communicates with ventral 
air store (white arrow) and with air store surounding metacoxa (black arrow). 
outer wall and in the extent of the dorsal opening between the inner 
and outer walls. 
The anterior portion of the outer wall of the lobe is dilated on the 
body (Fig. 23, EML) and resembles a weakly-developed postalar 
projection. Immediately anterolateral to the metacoxal process it 
forms a short anterior extension which fits against the wing-anchor- 
ing ridge (W) of the episternum. The posterior portion of the outer 
wall (C) is strongly indented on the body. The convex internal 
surface of this indented portion adheres to the inner wall of the lobe 
but elsewhere the two walls, like those of Diaprepocoris, are sep- 
arated by a distinct lumen. The dorsal opening into the epimeral 
lobe extends all the way to the base of the muscle process (MP) 
rather than ending anterior to the process as in Diaprepocoris 
(compare Point P, Figs. 22 and 23). Thus the posterior part of the 
lobe lies much closer to the abdominal process (AP) than in Diapre- 
pocoris. 
