1914.] NATURAL SCIENCES OF PHILADELPHIA. 325 



B. DISPOSITION OF THE OLFACTORY PORES OF OTHER 



HYMENOPTERA. 



In making a comparative study of the olfactory pores of Hymenop- 

 tera, 29 species representing 22 families have been used (those of 

 ants and hornets already described included). Since the pores of 

 only one specimen for each species were counted, the total number 

 of pores recorded certainly cannot be a fair average. Besides this 

 error, there is also a probable error of not less than 10 per cent, on an 

 average for all the specimens. In the smaller individuals, particu- 

 larly ants, the probable error is perhaps not more than 2 or 3 per 

 cent., but in the larger specimens, especially the hairy ones, this 

 error is perhaps more than 10 per cent. The pores on only the wings 

 and legs have been included in the total numbers. On all the stings 

 examined, pores have been found. The mouth parts of a few of the 

 specimens were hurriedly examined; all of them bear pores. A few 

 aiitennse were also hurriedly examined. None of the pores first 

 described by Hicks were found on these appendages, but this can be 

 definitely decided only after a critical study of the antennae has been 

 completed. No pores were found on the petiole or other parts of 

 the ant not already named. 



I. Distribution. 



Since all the variations relative to distribution are slight, only 

 the most important ones will be mentioned. In all the species 

 having two segments in the trochanter, the groups of pores ordi- 

 narily found on the femur occur on the second segment of" the tro- 

 chanter. Sometimes groups Nos. 1 and 2 on the front wing are 

 united. At other times group No. 2 is almost divided into two 

 separate groups. The groups of pores are usually located in areas 

 devoid of hairs, but occasionally the groups are closely bordered by 

 hairs. Sometimes a group is surrounded by clear chitin caused 

 by the group lying in an area of thin chitin. In short, the distri- 

 bution of pores of those species placed below the ants in the scheme 

 of classification is similar to the distribution of the pores in ants; 

 the distribution of those species placed above the ants in the scheme 

 of classification is more like to the distribution of pores in the 

 honey bee. 



II. Number. 



In regard to the number of groups and the total number of pores 

 found in the different species, the variations are great. Cimbex, 



