NO. 18 SENSE ORGANS OF COLEOPTERA — McINDOO 



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Fig. 12. — External view of compound and single olfactory organs and olfactory 

 pegs on distal half of last antennal segment of larva of Cotinis nifida. A, 9 com- 

 pound organs and 3 single ones on ventral side of antenna, viewed from a flat 

 surface, X 100 ; 2 of the compound organs at extreme tip are not shown. B, 6 

 compound organs, 4 single ones, and i group of olfactory pegs (Pg) on dorsal 

 side of antenna, viewed from a flat surface, X 100. C. external view of a com- 

 pound and a single organ, X 320 ; the small circles represent pore apertures. 



Fig. 13. — Internal anatomy of sense organs on antenna of larva of Cafitiis 

 nitida. A, longitudinal section through tip of antenna, showing innervation of 

 compound (PI) and single olfactory organs (P), and tactile hair (St) ; two- 

 thirds diagrammatic, X ifxi- (At this magnification the pore apertures are never 

 discernible). B, cross section through single olfactory organ from antenna, 

 X 500. Ap, pore aperture; Hyp. hypodermis ; NB, nerve branch; NF, nerve 

 fiber ; SC, sense cell ; SF, sense fiber ; and Tr, trachea. 



