D 



Fig 42. — First abdominal spiracle (left side) of American Cockroach. A. from 

 outside, open ; B. side view in section ; C. from inside, open ; D. from 

 inside, shut. The bow shaded in all the figures, the muscle shown in C. and 

 D. /, the inner opening ; /. the pouch. Magnified 70 times. From Miall 

 & Denny. 



