THE OLFACTORY SENSE OF ORTHOPTERA 409 



figures by widely separated dots, a few being present on each 

 the palpifer (fig. 8, a) and the maxillary palpus, several on each 

 the galea (fig. 8, b) and the lacinia (e), and a few on each the lab- 

 ial pulpus (/) and the ligula (fig. 9, j). The mentum bears 10 

 scattered pores (fig. 8, g). 



b. Pores on thorax. Most of the pores found belonging to the 

 thorax lie on the legs and wings and only a comparatively few are 

 present on the thoracic segments. On each front and middle leg 

 there are ten groups and several isolated pores, but on each hind 

 leg there are only six groups besides several isolated pores (figs. 

 10 to 15). On each wing there is one group and several isolated 

 pores (figs. 16 to 19). 



The pores are located more definitely as follows: Groups nos. 

 1 to 5 (figs. 10 to 15) lie on the trochanter; nos. 6 and 7 on the 

 femur; and nos. 8 to 10 on the tibia. All of these on the front 

 and middle legs are constant in position, although slight varia- 

 tions may be observed owing to the degree in which the leg is 

 rotated. On the smaller portion of the trochanter of the hind 

 leg (figs. 14 and 15) there are only four groups, probably nos. 

 1, 2, 4, and 5. This part of the trochanter, partially hidden by 

 the femur, is comparatively small and is found with difficulty. 

 The groups on it are shifted in position and no. 1 has 8 pores 

 instead of 3 as on the other legs; no. 2 has 9 pores instead of 10; 

 no. 3 is absent, but on the other legs it has 9 pores; no. 4 has 5 

 pores instead of 8 or 10; no. 5 has 13 pores instead of 10. 

 Groups nos. 6 and 7 on the front and middle legs lie at the prox- 

 imal end of the femur, but at the same place on the femur of the 

 hind leg there are no pores; no. 7 is wanting, but on the other legs 

 it has 10 or 11 pores. No. 6 is either absent or has migrated 

 down the femur (fig. 14) one-third the distance from the trochan- 

 ter; however, at this position there are 3 pores, but no. 6 on the 

 other legs has 13 pores. Groups nos. 8 to 10 lie near the prox- 

 imal end of the tibia; nos. 8 and 10, having 8 and 5 pores, respec- 

 tively, on the front and middle legs, are wanting on the hind leg, 

 and no. 9 has 4 pores instead of 5. 



A few of the isolated pores are constant in number and position, 

 while most of them are variable in disposition. The base of each 



