340 PROCEEDINGS OF THE ACADEMY OF [Apr., 



Fig. 7. — One of smallest pores from tibia of female of Formica. 



Fig. 8. — Two pores from group No. 2 on front wing of female of Formica. 



Fig. 9. — Two pores from group No. 3 on front wing of female of Formica. 



Fig. 10. — Two pores from group No. 4 on hind wing of female of Formica. 



Fig. 11. — Two pores from group No. 5 on hind wing of female of Formica. 



Fig. 12. — Six pores and a bunch of sense cells as actually seen in group No. 2 

 on front wing of female of Formica. 



Fig. 13. — Three pores, one sense cell, and hypodermis as actually seen in 

 group No. 7 on trochanter of female of Formica. 



Fig. 14. — Two pores with sense cells and hypodermis as actually seen in 

 group No. 8 on trochanter of female of Formica. 



Fig. 15. — Pore from group No. 6 on trochanter of female of Formica. 



Fig. 16. — Isolated pore from group h on trochanter of female of Formica. 



Fig. 17. — Two pores from a group on trochanter of dealated female of 

 C. pennsylvanicus. 



Fig. 18. — One of largest isolated pores from trochanter of dealated female 

 of C. pennsylvanicus. 



Fig. 19. — One of smallest isolated pores from same trochanter as in fig. 18. 



Fig. 20. — Three pores from group No. 2 on front wing of old winged female 

 of C. mela. 



Fig. 21. — Three pores from group No. 3 on same wing as in fig. 20. 



Fig. 22. — Three pores from group No. 2 on front wing of old winged male 

 of C. mela. 



Fig. 23. — Four pores and bunch of sense cells from stub of wing of old 

 dealated female of C. pennsylvanicus. This female had been kept in 

 captivity eight months before killed. 



Fig. 25. — Semidiagram of cross-section of front wing of female of Formica, 

 showing innervation of groups Nos. 2 and 3. X 280. As in fig. 26, harcl 

 chitin of wing is represented by solid black; soft articular chitin of wing 

 by dots, and hard chitin of thorax by broken lines. Owing to the broken 

 condition of the chitin, the nerves (N) could not be traced into these 

 wings, but they were traced into the wings of the honey bee and mud- 

 dobber. 

 Plate XII. — Fig. 26. — Semidiagram of cross-section of hind wing of female of 

 Formica, showing innervation of groups Nos. 4 and 5. X 280. 



Figs. 27 to 32, inclusive, are cross-sections through pores of hornet {Vespula 

 maculata). Fig. 27: One of largest pores, and fig. 28 is one of smallest 

 pores from tibia. Neither pore aperture was seen in section. Fig. 29: 

 Three pores on trochanter cut oblicjuely, showing pore apertures. Fig. 30: 

 One of smallest pores from a group on trochanter, showing sense cell. 

 Pore aperture was not visible. Fig. 31: Pore from femur. Fig. 32: 

 Three pores from front wing. 



Figs. 33 to 41, inclusive, are cross-sections through pores of muddobber 

 {Sceliphron cementarius) . Figs. 33 and 34: Two pores from two different 

 groups on trochanter. Figs. 35 and 36: One of largest and one of smallest 

 isolated pores from trochanter. Fig. 37: Pore from group on fenun*. 

 Fig. 38: Shows origin of internal anatomy of a large pore and sense cell 

 from tibia. Fig. 39: One of smallest pores from tibia. Fig. 40: Three 

 pores from group No. 2 on front wing. Fig. 41: Pore from thorax at 

 base of niche near articulation of front wing. 



Fig. 42. — Pore and sense cell from tibia of a worker honey bee. 



Figs. 43-79 show the relative sizes of the superficial appearances of pores 

 of various hymenopterous insects. In each figure, the larger pore is from 

 the femur and the smaller one is from the front wing. These pores are 

 the largest ones seen on these appendages. Below in the order named 

 are given (1) the figure number, (2) the name of insect, and (3) the relative 

 size of the insect. The relative sizes of the various insects were found as 

 explained on page 326. 



Vig. 43. — Citnbcx (tmcricana 6.00 



Fig. 44. — Macrophyla flavicoxce .- 1 .75 



Fig. 45. — Megarhyssa lunator 3.33 



