FAM. MEMBRACID.E 45 



CLASSIFICATION 



The classification of the Membracidce here adopted recognizes six subfamilies, following the 

 classical major divisions which were estabUshed by Fairmaire, Stal and Fowler. These subdivisions 

 are based on sound structural characters and have proven entirely satisfactory for taxonomic work. 

 Some authors («. g. Goding 1926) have seen fit to include the genus jEthalion in the fam. Membracida 

 as a subfamily but we do not see how such an assignment can be justified. The yEthalionida are quite 

 distinct from the MembracidcB in such important characters as genitalia, wing venation, sensory appa- 

 ratus, pronotal structures and in life histories, and we believe that these insects should be considered 

 as a separate family. The six subfamilies here recognized show not only good structural characters by 

 which they may be recognized, but there are few genera which show tendencies to overlap and indeed 

 very few which may be considered transitional. 



The subfamilies are divided into tribes, erected on more or less arbitrary characters. These 

 tribes are in turn divided directly into the genera of which 290 are considered as valid in this study, 

 and the genera are again divided directlj' into the species. No other subdivisions, such as sub-tribes or 

 sub-genera, are here recognized or considered. 



In the following systematic outlines, the characters are, for the most part, natural ones, and 

 we believe entirely suited to dichotomous keys, and sufftcient for the recognition of the divisions 

 indicated. In such keys, howevei , the number of characters which can be mentioned in each synoptic 

 pair is of course limited, and, in case of doubt, reference should always be made to the more complete 

 generic descriptions. 



TAXONOMIC CHARACTERS 



It is of course impossible to state positively the characters which should be considered of generic 

 value but after a careful study of those structures which in the Membracida seem to be most useful in 

 separating the genera the author has chosen a list of certain easily recognizable features which we 

 believe will serve this purpose. These have to do chiefly with the foUowing : 



1. The Head. Shape and position; structure of the base; form of the eyes; position of the 



ocelli; configuration of the inferior margins of the genae; appearance of the clypeus. 



2. The Prothorax. General shape and appearance of the pronotum; type of metopidium; 



appearance of humeral angles; structure of suprahumeral horns; shape and position 

 of posterior process; type of scutellum. 



3. The Tegmina and Hind Wings. Size and shape; free or covered; texture; condition 



of basal and costal margins; venation; number of apical and discoidal cells; shape of 

 tip; apical limbus. 



4. The Legs. Shapes and comparative lengths of femora and tibiffi; condition of trochanters; 



flattened or foliaceous parts; comparative length of hind tarsi. 



