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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 82 



but the other so-called olfactory organs, which are nothing more 

 than ordinary innervated hairs, are common only to the antennae of 

 the adult, although similar innervated hairs are also found on other 

 parts of both adult and larva. In the adult the olfactory pores were 

 found on the head capsules, legs, elytra, wings, and mouth parts, and 

 at the base of the antennae ; in the larva, on the head capsule, base 

 of antennae, mouth parts, clypeus, and second thoracic segment. The 

 individual and sexual variations found in the pores were small, al- 

 though the females have 13.7 per cent more pores than have the 

 males. 



K^ 



^ 



PB ;^p PW 



Fig. it. — External view of single olfactory organs and noninnervated hairs 

 on larva of Cotinis nitida, X 320. A, 4 organs from trochanter, showing pore 

 border {PB), pore aperture (Ap). and pore wall (PJV). B, 2 organs and a hair 

 from hypopleural region ; C, 2 organs from maxilla ; D, 2 organs and a hair 

 from labrum ; E, 2 organs from labium ; F, 2 organs and a hair from epicranium ; 

 and G, a hair from first antennal segment. 



On the larva of the green June beetle (Continis nitida L.) the writer 

 (44) foimd the olfactory pores unusually numerous and consisting of 

 two types. The single olfactory organs are isolated pores, not arranged 

 in groups. They were found on the antennae, all mouth parts, head 

 capsule, thorax, and legs, and average 1,359 pores per individual 

 larva. This number is slightly more than the total number of pores 

 found on the elytra, wings, and legs of an adult of the same species. 

 Their external anatomy is unusual in that the pore border (fig. 11, 

 PB) is radially striated, while the border around the hairs never 

 shows striae. The compound olfactory organs (fig. 12) are variously 

 shaped plates, each of which bears many apertures. They were found 

 only on the distal halves of the last antennal segments. Figure 13 

 illustrates the internal anatomy of the single and compound organs. 



