THE OLFACTORY SENSE OF COLEOPTERA. 417 



17, 18, 20, 21, 22, 24, 31, 48, 49), and from one to three pores were 

 found at the proximal end of each femur of Elater. 



While it is common to find one or more pores at the proximal 

 end of a tibia, many of these segments are entirely devoid of 

 olfactory pores. The greatest number of pores found on any 

 tibia at this place is nine. In each of the tibio-tarsal articulations 

 of the front and middle legs belonging to Cotinis from 7 to 11 

 pores were found. Pores were found in the tibial spines (Text- 

 fig. 2G and Plate II., Fig. 27) of 15 species (Nos. 9 to 11, 20 to 

 25) 31, 32, 34, 35, 45, 48). The pores usually lie on the bases of 

 the large spines. The largest number of pores found on a single 

 tibial spine is 12. Of the 50 species examined, Passalus has 

 the most pores on these spines. 



Pores were found on the tarsi of 13 species (Nos. i, 2, 4, 10 to 

 12, 16, 18 to 21, 25, 31). The greatest number found on a 

 single tarsus was 37. Osmus, one of the three apterous species, 

 has the most pores on its tarsi. 



Eleven species (Nos. 6, 26, 27, 29, 31, 32, 33, 38, 42, 44, 47) 

 were found with no pores on the legs except those on the tro- 

 chanters and on the tibial spines. Cyhister with 49 pores on all 

 six legs has the least number on these appendages, while Podabrus 

 with 341 pores on all six legs has the largest number. 



No special examination was made to find any structure other 

 than the olfactory pores, nevertheless, minute pores were seen 

 in 15 species (Nos. 7, 8, 14, 15, 16, 20, 25, 27, 29, 36, 40, 44, 45, 

 46, 48). These pores were seen on various parts of the beetles, 

 but particularly on the legs and elytra. They usually lie near 

 the bases of the hairs, but sometimes they lie a considerable 

 distance from the hairs. Since they are many times smaller 

 than the olfactory pores, without exception they are. probably 

 the pores belonging to hypodermal glands, as will be shown for 

 those of Epilachna on page 423. However, a careful comparative 

 study of these pores is needed before anything definite can be 

 said about them. 



Coxelus, the smallest species examined, has a total number of 

 273 pores which is the smallest number of all the winged species, 

 while Orthosoma, perhaps the largest species examined, has a total 

 number of 1,268 pores, which is the largest number of all the 



