Plate I. Pit sensilla on the antennae of the blowfly. 



Fig. 1. Longitudinal section through two coronal sensilla. Note the large 



scolopoid sheath at the base of the left-hand sensillum (x 12,300). 

 Fig. 2. Longitudinal section through a thin-walled sensillum (:< 14,000). 

 Fig. 3. Transverse section through a pit containing coronal sensilla ( < 6000). 

 Fig. 4. Transverse section through thick-walled sensilla. Note the bipartite 



scolopoid sheath (x 49,000). 

 Fig. 5. Transverse section through a pit containing nine thin-walled sensilla 



(X 4900). 



