448 THE BLOWFLIES oF NortH AMERICA 
PLATE 38 
Apaulina avium (Shannon and Dobroscky) 
Larva, third instar 
A. Posterior spiracle. 
B. Cephaloskeleton. 
Apaulina metallica (Townsend) 
Larva, third instar 
C. Posterior spiracle. 
D. Cephalic segments. 
E. Cephaloskeleton. 
