156 
Psyche 
[June 
Fig. 22. D. zealandiae; semi-diagrammatic lateral view of thoracico-abdominal 
region, prepared as in Fig. 21. Thoracico-abdominal membrane (TAM, mostly 
removed) attaches along posttergite (PT) and lateral edges of intersegmental ridge 
(IR) and sclerotized strip (SS). 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; spiracle communicates with ventral air store 
(white arrow) and with air store surrounding metacoxa (black arrow). 
The intersegmental boundary (Fig. 22, 3PH) is transverse in 
the dorsolateral part of the body. At the level of the opening into 
the epimeral lobe the boundary bends abruptly posteroventrally, 
forming a low internal ridge (IR). The ridge adheres to the inner 
wall of the lobe, obscuring the posterior part of the opening. Only 
mature specimens were available for this investigation; quite pos- 
sibly the opening is not obscured in newly-moulted individuals. 
At Point P the epimeral lobe becomes continuous with a narrow 
sclerotized strip (Fig. 22, SS) which runs posteromedially and ends 
in a muscle process (MP). All but the most ventral, posterolateral 
edge of this strip is concealed externally by the functional thoracico- 
abdominal membrane (Fig. 15, TAM; membrane mostly removed 
in Fig. 22), which attaches along this edge. The first abdominal 
spiracle (Figs. 15 and 18, SI) lies in the thoracico-abdominal mem- 
brane immediately lateral to the sclerotized strip. The anteromedial 
edge of the strip is more dorsal than the posterolateral edge and 
