Suborder Homoptera 



groups, each year. The tree-hoppers and the leaf-hoppers and 

 some of the other groups, however, are very poorly known, and, 

 in fact, the whole suborder, as it is represented in tropical 

 regions, is but slightly known. Collectors in out-of-the-way 

 places have neglected this group, and doubtless very many 

 thousands of species will yet be discovered and described. A 

 small group of American workers, including Messrs. Osborn, 

 Van Duzee, Baker, Gillette and Ball, are doing admirable work 

 upon the leaf-hoppers and tree-hoppers, but there is still room 

 for many more investigators of these interesting insects. They 

 are easily preserved and make an interesting collection. The 

 study of the scale insects may safely be left to the small army of 

 economic workers who have taken up their study during the 

 past ten years, but the plant-lice need many more students. The 

 difficulty of properly preserving the insects of this group, since 

 they must be kept in alcohol or formalin or mounted upon 

 microscope slides, doubtless deters many from entering upon 

 their study. But the life histories of very few of our North 

 American species are known, and many important and most 

 interesting facts are still to be learned about a host of species. 



Table of Families 



Beak plainly inserted in the head; feet with three segments; 



antennae minute, bristle-like i 



Beak apparently inserted bet\\'een the forelegs; feet with one or 

 two segments; antennae usually prominent, but sometimes 



wanting 5 



I — Ocelli three in number; the males with musical organs 



Family Cicadidx 



Only two ocelli or none ; males not musical 2 



2 — Antennae inserted in front of and between the eyes 3 



Antennae inserted on the sides of the cheeks beneath the eyes 



Family Fulgoridx 



3 — Prothorax not prolonged above the abdomen 4 



Prothorax prolonged into a horn or point above abdomen 



Family Memhracidce 



4 — Hind shanks with one or two stout teeth below and at tip 



w ith a crown of short, stout spines Family Cercopidce 



Hind shanks with a row of spines below ?2Lm\\y Jassidce 



229 



