6 LIST OF ILLUSTRATIONS. 



Page 

 FlG. 20. Expressing similar relation as in fig. 19 for material from Willow 



Grove, Pa 58 



21. Expresses similar relation as in fig. 19 for material from Gotha, Fla. 59 



22. Relation between melanism of second abdominal segment and clypeus 



of female. Cold Spring Harbor collection 61 



23. Relation between melanism of second abdominal segment and clypeus 



of female. Willow Grove collection 61 



24. Relation between melanism of second abdominal segment and re- 



maining segments similarly expressed for 100 specimens from 

 Gotha, Fla 62 



25. Similar relation for material from Willow Grove, Pa 62 



26. Correlation between pigmentation of second abdominal segment and 



clypeus of females in collection from Gotha, Fla 63 



27. Relation between melanism of second abdominal segment and remain- 



ing segments, expressed for collection from Cold Spring Harbor, 



N. Y 63 



